Ignition coil questions...

[Kenny_Z]

Red left me on the side of the road earlier today. I was stopped at a light in neutral and my idle around 800 per the dash gauge. Without warning the RPMs dropped to 0 and she wouldn't crank back up. I pushed her off to the side and tinkered a little. A guy in a very nice fox body Mustang stopped and was admiring the D while he was listening to the engine. He pointed at my silver Accell coil and said "That's the source of your problem. I've pulled many of those out of the Mustangs I repair and I've never seen one run right." I pulled the wire, reseated it, and Red fired right up.

On the way home I kept the radio off and listened to the engine closely. From about 2500 RPM up I could hear a misfire and could feel it in the car. Anything up to that point was surprisingly strong for a car that had just left me on the road.

Going from memory of the last time I put a multimeter on that coil I had 1.8 volts on the left hand side and about 7.5 or so from the right hand side. This was key on but not cranked. I'll have to take readings tomorrow when she's running. Last time I was messing with it I was so excited that Red started that I forgot what I was doing and took her for a short drive. I blame Delorean withdrawl...

[Farrar]

Are you sure you have the ignition coil correctly oriented? On some aftermarket coils you have to face the coil "backwards" (label against the firewall) to get the positive and negative terminals in the correct orientation for our cars. (You can run a car with the ignition coil wired backwards, but it will run like doo-doo.)

Farrar

[content22207]

Use the terminal markings (+ and -). That's what they are there for. Orienting a coil by a brand label means absolutely nothing -- what if there was no label?

Is your "left side" positive or negative? If you're only running 1.8 volts into the coil (obviously the ECU side of the circuit), your secondary spark is going to be very weak indeed.

Bill Robertson
#5939

[Farrar]

Orienting a coil by a brand label means absolutely nothing...

Nonetheless, I've seen people do it... :shrug:

It never hurts to rule out the obvious.

Farrar

[sean]

It never hurts to rule out the obvious.


True Dat! It is easy to become complacent with things like that and you can never assume the skill level of the OP's ability. But really, gotta pay attention to the hard markings on the coil.

[Kenny_Z]

I matched it up by positive and negative when I took off the old coil. However, I should have taken into account the previous owner's ability. He did have a mismatched set of plugs in the car. I could easily have a backwards coil and not know it. I'll trace the wires when I get home and make the ECU side is heading into the positive terminal.

If the coil is oriented correctly and I am only getting 1.8 into the ECU side then I'll need to search for the source of that low voltage. Is there a voltage range I should be looking to see off that terminal?

[stevedmc]

I pulled the wire, reseated it, and Red fired right up.

Are you talking about the wire that goes from the ignition coil to the distributor? This wire has come loose on my ignition coil before. I decided to fasten the wire with a tie wrap and it hasn't been loose since then.

[content22207]

I'll trace the wires when I get home and make the ECU side is heading into the positive terminal.

If you do that your ignition will never work right, no matter what brand of coil you use.

Bill Robertson
#5939

[Kenny_Z]

Yeah, the wire from the coil to the distributor. I did have an issue with the cable walking up the coil's connection during my tune up until I spread the metal connector enough to hold the wire down. The boot John put on that cable is too small for after market coils.

Even with it fully secured I feel like I've got a weak spark.

[content22207]

You've got a weak spark because you wired your coil up backwards.

Line in comes from the resistor grid. Line out goes to the ECU.

Bill Robertson
#5939

[Kenny_Z]

I'm not sure that it is wired in backwards yet but I'm not ruling it out. I simply put it in matching the previous coil's connections. Unfortunately I'm pretty weak when it comes to reading wiring diagrams. I was reading the wiring diagram posted in the resource section and just wasn't dumbed down enough for me. I assumed the positive wire comes from the ecu. Seems I was mistaken.

I've built networks that go from Oregon to Miami but I can't read one of those without the wires in front of me and time to make sense of it. When I rewired my Mustang I shelled out for the Painless wire system that had everything labeled. It was a brainless endeavor.

I'll know more once I get to the house and can put my hands on everything.

[content22207]

Bosch coils are labeled bass ackwards -- you can't match them to anything else: "15" is "+" and "1" is "-" (I just had to look up which was which in the Workshop Manual to refresh my memory -- stupid design).

With the label facing you, I'm pretty sure Accel coils have the positive terminal on the right. It seems every owner who tries to run an Accel brand coil wires it up backwards -- much moreso than Pertronix or MSD brand coils.

Just remember that the ECU performs the same function as old fashioned breaker points and you'll get everything pointed in the right direction.

Bill Robertson
#5939

[Bitsyncmaster]

The correct way is to hook the white/yellow (also yellow capacitor wire) goes to the + terminal. And the white/slate to the - terminal.

[Kenny_Z]

The coil is connected correctly. I'm getting 1.6 volts from the negative side and 6 volts on the positive side with the key on. The battery reads 12.4 volts.

[Kenny_Z]

Sorry, typing on my phone and hit enter too soon. With the engine running I'm getting 6.8 from the positive and 10.2 from the negative.

[content22207]

You are measuring something wrong. The coil itself should have .5-1 ohm resistance (it is full of wire), so there's no way the negative terminal can have more voltage than the positive terminal.

Bill Robertson
#5939

[Bitsyncmaster]

You are measuring something wrong. The coil itself should have .5-1 ohm resistance (it is full of wire), so there's no way the negative terminal can have more voltage than the positive terminal.

Bill Robertson
#5939

Each meter does different things when you measure DC voltages that are switching on and off. That is why I always ask people to read the voltage with the engine off. But your correct the average voltage on the - should be less than the +.

If you look at the - voltage on an oscilloscope your will see peak voltages of 130 volts. It's a very short pulse and that is probably upsetting his DC meter reading.

[Kenny_Z]

I'm going to blame the phone again. I was getting 6.8 from the negative terminal and 10.2 from the positive. Sorry, I shouldn't think and type.

I went through and cleaned all the grounds and positive connections I could get to except the alternator. I'll do that when I've got more light outside. After the cleaning I got 6.8 from the negative side and about 10.5 from the positive. The alternator was putting out about 13.5 volts. It really doesn't feel like a voltage problem unless I have a bad engine ground which I'll be adding another, easier to access one this weekend.

I let Red warm up to operating temperature. I pushed the throttle up to about 2500 and then let off as if I was pushing in the clutch. The RPMs fell off fast and it sounded like the engine stumbled a bit before she started to let off. If I gradually let off the throttle it didn't do that. Could my idle speed motor be sticking?

Another thing, I could smell how rich she's running after the warm up. Could she be suffering from vapor lock? I realized the stalling has always occurred after she's done at least 20-30 minutes worth of driving.

[content22207]

You only get about half a volt fluctuation while the ignition is switching.

I just measured my service truck's coil (DeLorean's front end is up on blocks -- don't want to start it, plus it would bother the neighbors): ~10.5 volts in, ~6.5 volts out (Pertronix coil).

You posted same time I did -- looks like your coil is oriented OK.

Put a timing light on one of the spark plug leads and watch how it behaves as you rev the engine.

Bill Robertson
#5939


Could she be suffering from vapor lock?

Not with a pump in the tank.

Bill Robertson
#5939

[dn010]

Did you check for vacuum leaks?

[Kenny_Z]

I was looking for vacuum leaks but didn't find any. I'm going to get something to spray a mist and try again tomorrow.

I was reading another forum about PRVs and this stalling issue. Unfortunately the thread didn't conclude with a resolution but it did give me things to try. Step 1, clean the idle motor. Step 2, check the throttle/butterfly valves for clogs. My intake was saturated with old oil I'm leaning toward this being at least part of the problem.

I compared the D's voltages with my Stang's and Red came out on top with slightly higher voltages. That surprised me as my old 289 runs extremely well with zero issues. I'm leaning further away from this being an electrical issue. I'm going to dig out my timing light tomorrow. I managed to misplace it at the beginning of the summer.

[Kenny_Z]

The new ground seems to have really helped. The misfire over 3000 RPMs is gone. On my test drive I pushed her up to 4500 RPMs in 3rd and didn't hear or feel any misfire or hesitation. She's starting a lot faster and the rich exhaust smell is gone. I'm pulling closer to 14 volts from the alternator now.

She didn't stall out on me completely but my RPMs are still flakey when pushing in the clutch. It only happens when she's warmed up. I don't have much of an idle hunt after the initial start up hunting. Once she evens out the rpms are solid until the engine is fully warmed up. It's weird, the voltage meter drops and if I have the headlights on they dim quite a bit. The RPM gauge goes up but the motor sounds like it loses RPMs. It sits like this for a second or so and then the voltage meter goes up, the RPMs sound like they return to normal, and the RPM gauge drops to between 700 and 800. Then about a second or so later it starts over.

I've got a replacement O2 sensor to install and I still have to clean the idle motor and butterfly valves. I may do the fuel accumulator replacement while I'm at it.

[dn010]

You should check the condition of your cap / rotor if it has been a while. It may be time to replace. Personally, I could never get my D to run decently on any coil other than the original one - there were always issues with higher output ones. If you have a stock one throw it back in and see if your issues persist, it is worth a shot.

[Kenny_Z]

I just replaced the cap and rotor with units from John Hervey. The old coil was cracked and ended up falling apart (literally) after it was removed. I do have a lower voltage coil from an old I6 Ford that I could try. Right now the priority is lunch :D

[content22207]

I know several owners, myself included, who are running true HEI with excellent results.

Bear in mind that ignition coil secondary voltage is directly proportional to its input. You can not run only 6-8 volts into a high winding coil and expect anything close maximum rated output (most HEI coils are rated at 12-14 volts input). You will get more secondary voltage than a stock Bosch coil simply by virtue of the higher number of windings, but certainly not anything close to 40,000 volts.

Bill Robertson
#5939

[ramblinmike]

I know several owners, myself included, who are running true HEI with excellent results.


Are you running 12v to the coil with the stock Bosch amp or the Duraspark you were running? I know guys run 12v to the Duraspark all the time.

[content22207]

I am running 12.5 volts into a Pertronix coil. Voltage is something like 8 or 9 volts to the Bosch ECU at the other end. I was only test driving a Duraspark unit for Byrne. He gave me his dead Bosch unit, which I will use to make another adapter to carry with me in case my ECU dies.

My resistor grid is wired in parallel (that is how I get 12.5 volts into the coil):
4258
Pertronix coils can of course handle full charging voltage no problem. I only step it down for the ECU's benefit. I don't trust Bosch ECU's any further than I could throw one of the damn things. If I was running an original Ford Aerospace Duraspark ECU, I wouldn't reduce input voltage at all.

The biggest advantage of HEI is the ability to open up the plug gap. .026" is ridiculously small. No wonder stock DeLoreans run like crap. The benefits of wider plug gaps have been known for decades. Nearly every other manufacturer was already running .05" plug gaps when DeLoreans were new in the showroom. GM introduced HEI in 1971. DeLorean ignition was obsolete even before these stupid little cars were nothing more than a stainless steel fantasy in the back of JZD's mind. The man was vice president of the company that pioneered HEI, for crying out loud -- he should have known better.

Speaking of which: DO NOT OPEN YOUR PLUG GAP IF YOU ARE STILL RUNNING SUBSTANDARD DELOREAN 6-8 VOLTS INTO THE COIL, NO MATTER WHAT KIND OF COIL IT IS (can I hear an "Amen" Steve?). The stock resistor grid is really better suited for breaker points than breakerless ignition.

Bill Robertson
#5939

You can get away with smaller plug gaps in high compression and forced induction engines because the mixture is easier to ignite. Some owners claim that larger plug gaps are actually counter productive in those circumstances.

In a low compression engine, like the stock DeLorean PRV, the mixture is harder to ignite. Leaning the mixture out for fuel economy and emissions exacerbates the situation. That is one reason American manufacturers were so quick to adopt HEI in the early 70's.

A Society of Automotive Engineers' study from the time: http://dmctalk.org/showthread.php?652-Running-a-DeLorean-on-Ford-Ignition&p=7222&viewfull=1#post7222
I found it particularly fascinating that wider plug gaps also yielded benefits similar to increased gap projection (you don't need to change spark plug length -- just open the gap up).

Bill Robertson
#5939

[stevedmc]

Speaking of which: DO NOT OPEN YOUR PLUG GAP IF YOU ARE STILL RUNNING SUBSTANDARD DELOREAN 6-8 VOLTS INTO THE COIL, NO MATTER WHAT KIND OF COIL IT IS (can I hear an "Amen" Steve?). 9

Preach on brother!

[content22207]

This is how crappy DeLorean ignition is: if you don't bypass one of the resistors, you can't even start the damn car. Who dreamed this stuff up -- it's stranger than fiction.

I've seen cars with one ignition resistor, but until I bought a DeLorean I never saw one with two.

Bill Robertson
#5939

[Kenny_Z]

I didn't get to spend a lot of time with Red today but I did get to clean the idle motor and the butterfly valves. Unfortunately the idle issue still remains but I did get a surprise from the car. When I went to crank her up I expected the usual 5 to 10 seconds of cranking before firing up but this time I had a split second start up. I had to look around and make sure I was actually in the Delorean. It may have been a fluke start up though.

Tomorrow I hope to do some more grounding. I'm using Bitsync and Bill's ideas as a guide. I think the chassis length ground cable and grounds for the inertia switch are both within my abilities to perform. The testing I did today was on a cool engine. When I turned on the headlights, A/C, or switched on the vent fans I got a severe voltage drop. Running all 3 at once made the motor sound like it was struggling to stay afloat. Grounding the engine better fixed the stalling and misfires but I think my current idle drop issues are in the accessories.

[Bitsyncmaster]

This is how crappy DeLorean ignition is: if you don't bypass one of the resistors, you can't even start the damn car. Who dreamed this stuff up -- it's stranger than fiction.
Bill Robertson
#5939

That is not true. And everyone can test it just by pulling the blue/yellow wire off the resistor and try to start that way. Now if you have a weak battery then you may only start with the bypass.

[DCUK Martin]

This is how crappy DeLorean ignition is: if you don't bypass one of the resistors, you can't even start the damn car. Who dreamed this stuff up -- it's stranger than fiction.



You really haven't got a clue, have you Bill?

The resistors are there to limit current to the coil. This is Ohm's law in action. The most basic principle of electrics which you obviously still haven't grasped.

When cranking, the battery is being loaded quite hard on other stuff, so terminal voltage and its ability to supply current to the ignition system is reduced. Hence the laughably simply system to short out one of the resistors and provide the coil with extra current from the available voltage. It's only really necessary on a cold damp morning.

[content22207]

You really haven't got a clue, have you Bill?

The resistors are there to limit current to the coil. This is Ohm's law in action. The most basic principle of electrics which you obviously still haven't grasped.

Current = Voltage / Resistance. If you increase resistance, current will be reduced -- it's a mathematical certainty.

The stock resistor grid produces 1 ohm of resistance: 13.5 / 1 = 13.5.
My rewired resistor grid produces .25 ohm of resistance: 13.5 / .25 = 54.

We're talking about high performance coils here, not crappy Bosch coils (apparently the OP's Bosch coil physically disintegrated -- sounds pretty crappy to me). Pertronix coils are designed to operate with no resistance on the line in.

Any owner who upgrades his or her ignition coil, as the OP did in the first post of this thread, but leaves the stock resistor grid intact is significantly limiting potential benefits of making the change in the first place. Of course you should follow manufacturer's recommended wiring. If Accel wants one resistor on the input (I'm hypothesizing here -- I don't know for sure they do), rewire the resistor grid using one loose end and the common terminal. The only reason I'm running any resistance is because I don't know if the Bosch ECU is voltage sensitive at all. My 1969 Lincoln engine (Pertronix ignition ECU) operates at full charging voltage.

Resistors reduce voltage, and ultimately current, by converting electrical energy into heat. Once that happens, the energy is gone -- it will never come back (into the original electrical circuit -- heat from the resistors will heat up the air around them, burn anything that touches them, etc).

Bill Robertson
#5939

[Bitsyncmaster]

Bill, your correct that the current = voltage divided by the resistance. But to compute the current through the coil, you need to account for all the resistance.

The standard setup of one ohm resistor (two 0.5 ohm) and the standard coil resistance of about one ohm, plus the wire resistance. Lets just say the wire has no resistance.

So the current would be 13.5 volts divided by two ohms. So the circuit has 6.75 amps.

So your setup with 0.25 ohms (with the coil resistance at 1 ohm) would result 10.8 amps.

Now if you start changing coils with different resistance you can get into trouble not accounting for the resistance. If your coil has two ohms then you should not run any resistance but then when you start the car on a cold morning with a low charged battery you may not have enough current to provide enough spark.

All the coils I have seen recommend running from 6 to 10 amps. If your run higher currents your coil will overheat and loose efficiency.

[DCUK Martin]

Thanks Dave, you've saved me that effort! Bill, you need to read up on "potential divider resistor networks". See if you can wrap your brain around the wheatstone bridge circuit for example :evilgrin:

In addition, I repeat for your benefit that you can't simply treat a coil as having a "resistance of 1 ohm" (or whatever) because it's an inductor and its very fucntion relies on transient behaviour.

Dave, maybe you can enlighten us as to the effect of higher currents on the ignition amp? I know they aren't prone to going pop, but I also know I couldn't get my turbo engine to run with anything other than a stock coil. I'm convinced there's some component matching going on there - that the amp is optimised for a certain current and for the coil's specific inductance ?

[content22207]

All the coils I have seen recommend running from 6 to 10 amps. If your run higher currents your coil will overheat and loose efficiency.

Not Pertronix coils:
4261

Bill Robertson
#5939

[DCUK Martin]

Bill, clearly your ability to mis-read instructions so they say what you want them to extends beyond this forum.


If the vehicle in which the Flamethrower 2 coil is installed has a ballast resistor or resistance wire, and is equipped with the ignitor 2 or a capacitive discharge system... the ballast resistor may be removed.
....
If the vehicle is equipped with a ballast resistor... and is NOT equipped with one of the systems mentioned above, the ballast resistor should NOT be removed.


Is there something about this message I am misunderstanding?

Edit: I note with interest the very first sentence on that document. Care to argue that too?

[content22207]

Is there something about this message I am misunderstanding?

Nope:


... The only reason I'm running any resistance is because I don't know if the Bosch ECU is voltage sensitive at all....


Edit: I note with interest the very first sentence on that document. Care to argue that too?

Happy to: "In stock applications, with not one but *TWO* ballast resistors cutting coil input voltage to a ridiculously low 6-8 volts (really better suited for breaker point ignition than breakerless ignition), the manufacturer's recommended spark plug and spark plug gap will work best."

Can I hear an "Amen," brother Steve?

Poor Martin has been predicting the demise of my ignition ever since it was first upgraded, sometime in 2003. Since then it has traveled from New York to New Orleans, and as far west as Kentucky. Curiously, the only dead Bosch ECU I've ever seen came off a car with stock ignition.

Motor on, boys.

Bill Robertson
#5939

[Bitsyncmaster]

Dave, maybe you can enlighten us as to the effect of higher currents on the ignition amp? I know they aren't prone to going pop, but I also know I couldn't get my turbo engine to run with anything other than a stock coil. I'm convinced there's some component matching going on there - that the amp is optimised for a certain current and for the coil's specific inductance ?

I think the stock ignition ECU could probably handle more current then our 6 amps. It's only the output driver, PC board and connector that would set the limit. The ECU driver is connected to the coil with 18 AWG wire so that is why you are seeing 1.5 to 2 volts on the coil -. The output transistor drops about one volt and the wire the rest.

DC resistance is important. It sets the current when the "points" remain closed. That current is what drives the coil into saturation (magnetic). Then when the current is removed the collapsing magnetic field produces the spark voltage. So the inductance does affect how fast the field changes and hence the output voltage.

[DCUK Martin]

Happy to: "In stock applications, with not one but *TWO* ballast resistors cutting coil input voltage to a ridiculously low 6-8 volts (really better suited for breaker point ignition than breakerless ignition),

What's the resistance of "a ballast resistor" then, Bill? Could it not be that the DeLorean actually has "one" resistor made of two halves?

I have never "predicted the failure of your ignition system" I've simply recommended other people not copy you because your reasoning for changing the stock system is rooted in your own ignorance.

[DCUK Martin]

DC resistance is important. It sets the current when the "points" remain closed.



The ballast resistor and the coil's parasitic resistance does that. Measuring the DC resistance of the coil doesn't tell you the inductance of the coil and therefore how it will behave to a unit step... (which looks like an open circuit initially).

[sean]

I have never "predicted the failure of your ignition system" I've simply recommended other people not copy you because your reasoning for changing the stock system is rooted in your own ignorance.

Sometime it's not ignorance but rather he does not wish to deal with hard things. Take for example his view on fuel pump covers which he now suggests owners leave off and install a water dam because:

Pump covers suck. They are a PITA to install, they shrink with time, and they crack.
taken from Farrar's blog thread (http://dmctalk.org/showthread.php?93-Farrar-s-car-blog&p=14338&viewfull=1#post14338)

[Bitsyncmaster]

The ballast resistor and the coil's parasitic resistance does that. Measuring the DC resistance of the coil doesn't tell you the inductance of the coil and therefore how it will behave to a unit step... (which looks like an open circuit initially).

Yes the inductance will change a lot when the current is changing but that is only for a very short time. The rest of the time it is DC resistance. Now if the input was a sine wave that would eliminate any DC resistance importance because the current would always be changing.

I think our cars used two resistors because they could not find a coil with the proper characteristics. It would be better to use one resistor for starter bypassing with the proper coil.

[content22207]

I think our cars used two resistors because they could not find a coil with the proper characteristics. It would be better to use one resistor for starter bypassing with the proper coil.

Read up on the history of the Bosch Blue coil. It debuted in the late 1960's, when most ignitions were still breaker point. The Bosch Blue coil was designed to produce optimal spark from the ~6 volts primary that was then the industry standard (6 volt Volkswagen owners -- that's 6 volts car voltage -- couldn't buy them fast enough).

Fast forward to 1981. By then, the Bosch Blue coil was looking very dated indeed. Nearly every manufacturer had upgraded primary coil voltage to at least 10 volts. Nearly manufacturer was running ~.05" plug gaps that higher voltage coils made possible.

It cracks me up when owners claim that DeLorean ignition was optimized for performance. Quite the opposite -- it was dumbed down for the coil.

Bill Robertson
#5939


I've simply recommended other people not copy you because your reasoning for changing the stock system is rooted in your own ignorance.

Actually, my reasoning for changing the stock system is rooted in increased performance.

Bill Robertson
#5939


Sometime it's not ignorance but rather he does not wish to deal with hard things.

Nothing quite like impartial and objective moderation, eh?

With all due respect, it is less hard (easier) to leave a stock ignition in place than it is to do the research and make the changes necessary to upgrade ignition to 1981 standards, much less 21st century standards.

Bill Robertson
#5939

[sean]

Nothing quite like impartial and objective moderation, eh?

It truly rocks!

[ramblinmike]

Regardless of everyone's position on the stock vs. modified coil/ignition, everyone should at least agree that the stock plug gap is pretty small.

As the years went on every car manufacturer has found a way to increase secondary voltage and with it the plug gap.

A stock system works well. That has been proven through millions of real-world miles cars with a similar setup have put on the road. What I don't understand is why a car company would base their 'new' electronic ignition around the use of an off-the-shelf coil. If they were putting the money into developing this new system why not develop a new a new coil to take advantage of the breakerless ignition?

Bosch wasn't the only one to do this. Ford did the same thing over here. I just don't understand why they would stop at 6-8v at the coil. They knew in the 60's that increased primary voltage was the way to go for performance and economy. They wouldn't have resorted to dual-point distributors (and the associated headaches) if they didn't.

[content22207]

In the 1970's Ford used 10.5 volts primary (Duraspark breakerless ignition). Plug gaps were .044".

Bill Robertson
#5939

[ramblinmike]

In the 1970's Ford used 10.5 volts primary (Duraspark breakerless ignition). Plug gaps were .044".

Bill Robertson
#5939

Here's where I found the info I was basing my statement:

http://www.autozone.com/autozone/repairguides/Ford-Ranger-Bronco-II-1983-1990-Repair-Guide/DISTRIBUTOR-IGNITION/Dura-Spark-II-Ignition-System/_/P-0900c15280077d43

From the above troubleshooting guide:
"If no spark occurs, measure the voltage on the battery side of the coil.

Less than 6 volts - Repair the wire carrying current to the battery terminal of the coil and repeat test.

If voltage is 6-8 volts - Substitute, but do not install, a known good module and repeat the test. If spark then occurs, reconnect the original module to verify its being defective. Replace as required. Refer to step 10 if the battery voltage is present."

This is not a Ford document FWIW.

[Bitsyncmaster]

Automotive coils need to switch 5 to 10 amps to work. It does not mater if it takes one volt or 100 volts to get that current in the primary. The output voltage is produced when the the current is switched off (open points) so at that time your + side of the coil will be 13.5 volts no mater if you have no resistor, 1 ohm or a 1000 ohm resistor.

[DCUK Martin]

Actually, my reasoning for changing the stock system is rooted in increased performance.


Give me detail - how much performance did you gain? Put your money where your mouth is....

[content22207]

Are you calling the Society of Automotive Engineers, and nearly every car manufacturer of the past quarter century, liars? I recommend pages 53-55 (6th through 8th pages of the scans): http://dmctalk.org/showthread.php?652-Running-a-DeLorean-on-Ford-Ignition&p=7222&viewfull=1#post7222

We can't really do anything about spark duration, given the small diameter of our distributor caps, but there is plenty a DeLorean owner can do to increase secondary voltage and open up his or her plug gaps.

You are wrong -- I humbly suggest that you learn to live with that reality.

Bill Robertson
#5939

[Kenny_Z]

Hey guys, I know I'm new around here and all but I've run a forum for the better part of 12 years so I think I'm qualified to speak on this.

You've got someone here that's posted a thread looking for some troubleshooting ideas and it has since devolved into a "my way is better" free for all. If I didn't understand the ways of the internet I'd think my thread was just hijacked for some egos to throw their weight around and I'd leave the forum with an unfixed problem and a sour taste for the Delorean community in general.

Up until my last post the conversation and the people involved were really helping me and I did improve my car. This little argument didn't help in the least. I understand the two sides, and honestly, I don't care either way nor do I care who started it. It is your car, do what you want.

All I'm trying to say is, please try to be a little respectful of what type of thread you're in before arguing. I've noticed so many troubleshooting threads never get resolved because of distractions and it is a great loss to the community. Imagine if someone had actually said "Eureka, this is what I did to fix my problem!" and the next guy searches, finds that info, fixes his issue, and doesn't have to ask the community?

[ramblinmike]

Hey guys, I know I'm new around here and all but I've run a forum for the better part of 12 years so I think I'm qualified to speak on this.

You've got someone here that's posted a thread looking for some troubleshooting ideas and it has since devolved into a "my way is better" free for all. If I didn't understand the ways of the internet I'd think my thread was just hijacked for some egos to throw their weight around and I'd leave the forum with an unfixed problem and a sour taste for the Delorean community in general.

Up until my last post the conversation and the people involved were really helping me and I did improve my car. This little argument didn't help in the least. I understand the two sides, and honestly, I don't care either way nor do I care who started it. It is your car, do what you want.

All I'm trying to say is, please try to be a little respectful of what type of thread you're in before arguing. I've noticed so many troubleshooting threads never get resolved because of distractions and it is a great loss to the community. Imagine if someone had actually said "Eureka, this is what I did to fix my problem!" and the next guy searches, finds that info, fixes his issue, and doesn't have to ask the community?
You are right. Sorry, man.

[content22207]

The problem is: some people buy a performance coil, like your Accel coil, and assume that alone gives them HEI. Doing such *HAS* led to problems in the past, like owners opening up the plug gap and creating engine misfires. Your Accel coil is probably fine, despite anything that fellow in the Mustang told you, but you do need to be aware of what it is, and what it isn't.

Bill Robertson
#5939

[Kenny_Z]

Yeah, I don't think it is the coil now. The new ground to the engine improved my spark which the Mustang guy may have interpreted as a bad coil. I didn't think the coil was going to give me a better spark, it really was just the closest thing I could locally get to a stock D coil once I found the cracks in my old one.

I didn't get much accomplished today because I spent most of the day working on my mom's van. She was having brake problems and mom's safety comes before the D any day of the week. I did have enough time to rig up a test ground cable before the rain started. I stuck some alligator clips on the end of a 20 foot 10 AWG cable. I stuck one end to the ground point for my headlights/cooling fans and the other end to the battery. This greatly improved my voltage drop when clicking on the headlights and AC so I know I need to continue with my plan to get a stronger ground on the front. My vent fans are still causing a massive voltage drop so I think I need to find their ground under the dash and use my test on them.

So now I have 3 questions:
Where can I find the ground connection for the vent fans?
Where the heck is the inertia switch hiding?
And what are these two disconnected wires I found?
http://uploads.m-cgi.com/kennyz/Delorean/orphanwires.jpg

[content22207]

On an automatic those go to the bulb that illuminates the shifter.

Bill Robertson
#5939

[stevedmc]

I have never "predicted the failure of your ignition system" I've simply recommended other people not copy you because your reasoning for changing the stock system is rooted in your own ignorance.

For what its worth I have copied Bill's ignition mod, and a few others, and I do take bathes in noodles.

[David T]

All too often someone gets the idea that bolting in a new, different part will give them better performance, gas mileage, reliability, <blank> etc. You can fill in the blanks. If it was that easy the original manufacturer would have done it. In some cases they actually do see some improvement only because the part they replaced was old, worn, the wrong one, or defective. There is little if anything to be gained by putting "performance" parts into the ignition system. If every part you could bolt on to the car added the performance each claimed you could theoretically double the HP of the car. Who is going to believe THAT! A BIG problem with deviating from stock is that it becomes near impossible for anyone to help when the car has a problem. Too many variables and no good place to start troubleshooting. For a street driven car reliability is very important. To a big extant more important than a small, temporary increase in performance. Another thing to remember is most systems are like chains. Only as strong as the weakest link meaning if you don't improve the WHOLE system, improving one part of it does not improve what the whole system can do. As Martin said, "Show Me!" Put it on a dyno and show the numbers. Till then it is just a pretty and expensive part. I swear that my car always runs better after I clean it or change the oil. A very subjective effect. After spending money on a performance part you expect the car to run better, faster, etc!
David Teitelbaum

[content22207]

... Till then it is just a pretty and expensive part.

Pertronix coils cost about half as much as a Bosch coil -- they are a pretty and INexpensive part.

HEI discsussions probably should be continued here: http://dmctalk.org/showthread.php?1334-High-Energy-Ignition-%28HEI%29.

[stevedmc]

Pertronix coils cost about half as much as a Bosch coil -- they are a pretty and INexpensive part.

Lets suppose a person wants to keep their ignition somewhat stock and wants to save money at the same time. Couldn't a persion replace a bad bosch coil with a Pertronix coil (they cost about $40) and leave everything else alone such as plug gap and resistor wiring?

I kept my plug gap stock until I rewired my ignition resistor and everything seemed to be fine. Obviously you wouldn't get a performance boost but it should work just fine.

[content22207]

Obviously you wouldn't get a performance boost but it should work just fine.

You will get a small performance boost. High winding coils produce more secondary voltage than low winding coils can from the exact same input voltage.

Bill Robertson
#5939

[DCUK Martin]

Hey guys, I know I'm new around here and all but I've run a forum for the better part of 12 years so I think I'm qualified to speak on this.

You've got someone here that's posted a thread looking for some troubleshooting ideas and it has since devolved into a "my way is better" free for all. If I didn't understand the ways of the internet I'd think my thread was just hijacked for some egos to throw their weight around and I'd leave the forum with an unfixed problem and a sour taste for the Delorean community in general.

I for my part only argue with Bill when he takes to his soap box with inflated opinions (expressed with suitable Bill-ish flamboyance) which are rarely backed up by engineering fact. You say "free for all"? I'd say no, it isn't. It's a "free for Bill" - at least that's how he treats the forum in general.

I want a newbie searching the archives to see both sides of the coin.


Are you calling the Society of Automotive Engineers, and nearly every car manufacturer of the past quarter century, liars?

*sigh*. No, I'm asking you to prove that with your ignition modification, you achieved anything more than could be achieved with new stock components.

[content22207]

*sigh*. No, I'm asking you to prove that with your ignition modification, you achieved anything more than could be achieved with new stock components.

This conversation is best moved to an HEI specific thread: http://dmctalk.org/showthread.php?1334-High-Energy-Ignition-%28HEI%29

[sean]

Please start moving the HEI discussion to where bill posted: Here (http://dmctalk.org/showthread.php?1334-High-Energy-Ignition-%28HEI%29)

[Kenny_Z]

I finally beat the problem. I found that I was getting 12.35 on the battery but only 11.4 at the positive post on the right hand side of the engine bay. With the car running I got about 13.5 but this quickly fell as I turned on accessories, especially the AC, all the way to about 8 volts. As the car hunted for idle it would drop even lower. So I replaced the ground cable from the battery to the chassis (2 gauge) but grounded it to the transmission instead. To me this seemed to be way easier than trying to replace the positive cable. I figured I was going to replace it if I found the positive was the issue so I did it first. After that, I got 12.35 at the battery and 12.35 at the positive ground post. As I turned on accessories I only dropped from 13.5 volts to 12.25 at the lowest at idle (AC max, fans full, and high beams on). I also ran a 4 gauge cable from the front ground to a bolt I found (doing nothing) running through the firewall and grounded some of the underdash grounds to this terminal.

A nice drive proved out the fixes. Now if she'll stay this fixed for awhile.

[DeLorean03]

I finally beat the problem. I found that I was getting 12.35 on the battery but only 11.4 at the positive post on the right hand side of the engine bay. With the car running I got about 13.5 but this quickly fell as I turned on accessories, especially the AC, all the way to about 8 volts. As the car hunted for idle it would drop even lower. So I replaced the ground cable from the battery to the chassis (2 gauge) but grounded it to the transmission instead. To me this seemed to be way easier than trying to replace the positive cable. I figured I was going to replace it if I found the positive was the issue so I did it first. After that, I got 12.35 at the battery and 12.35 at the positive ground post. As I turned on accessories I only dropped from 13.5 volts to 12.25 at the lowest at idle (AC max, fans full, and high beams on). I also ran a 4 gauge cable from the front ground to a bolt I found (doing nothing) running through the firewall and grounded some of the underdash grounds to this terminal.

A nice drive proved out the fixes. Now if she'll stay this fixed for awhile.

Well done, bud. This 4 gauge wire - I want to see this on Saturday at the show. I'm interested in this. So you basically just re-grounded the main negative terminal of the battery to the transmission rather than the frame? In essence, you installed your own "Hervey grounding wire kit" - is that what I'm understanding ? If so, I want you to help me with my kit when I go to install it!

As for the bickering, welcome to the forum, futureboy.