Running a DeLorean on Ford Ignition

[content22207]

Later this month I will be traveling to help an owner with persistent ignition problems. I made him a Bosch to Duraspark ECU harness adapter in case his ECU is the culprit.
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How does a DeLorean run on a Duraspark ECU versus Bosch? Indistinguishably.

Duraspark ECU's do have a couple of advantages over Bosch:
1) Stock item at any parts house
2) Cost $28
3) Lifetime warranty

Bill Robertson
#5939

[propony]

Very cool! Where did the Bosch plug come from? Did you source this from a donor car of some flavor?
Is the module the "blue" variety?
Would you consider posting the wiring schematic for your invention?
Curt

[DCUK Martin]

What has he tried replacing? The stock system only has 3 components...

[content22207]

Every test I have eMailed him to perform has come back positive: 8-12v into the coil, ice pick light flashes on the negative side, 630 ohms across the distributor pickup, ohm reading jumps all over the place while the distributor is rotating, etc. Since the ice pick light flashes, his Bosch ECU should be OK. I honestly have no idea what the problem is. I'm going down there with a couple of distributors, and of course a Duraspark module. We're also going to make him a set of MSD plug wires. By the time I am finished, he *WILL* have ignition.

This isn't the first time I've run a DeLorean on Duraspark. I temporary put a module on Rich Acuti's car many years ago. We did that with a series of jumper wires around the engine compartment, however, not a single adapter in the ECU compartment.

If I can find another Bosch ECU in the junkyard (to donate the male end), I am going to make an adapter for myself. Bosch ECU's seem to hold up well enough, but there definitely is a certain security knowing that I can get a replacement ECU at the nearest Autozone or Advance should something go wrong (for $28, I might just buy the ECU ahead of time and keep it in the car).

Bill Robertson
#5939

[content22207]

Forgot to mention the best thing about running Ford ignition: no one can give me any flack about my plug gaps (Ford's 1970's/1980's breakerless spec was .044" across the board).

Bill Robertson
#5939

[DCUK Martin]

Has he tried new leads, cap and rotor, spark plugs (all the standard stuff). As i've explained, testing components under DC conditions only tells you so much.

[content22207]

Trust me: there is a lengthy eMail history behind this problem. Since I only live a couple of hours away, the best thing to do is put the texts away and go down there in person.

He is upgrading to MSD wires at my suggestion because they are the best spark plug wires available. Totally run circles around carbon fiber wires. MSD's are made of real wire, so chances of them ever fatigue breaking are basically non-existent. Their insulation jacket is also nearly 25% thicker.

Bill Robertson
#5939

[sean]

Has he tried new leads, cap and rotor, spark plugs (all the standard stuff). As i've explained, testing components under DC conditions only tells you so much.

I'm pretty sure Bill is "fixing" Byrne's problem:
http://dmctalk.org/showthread.php?379-No-Ignition-Spark&p=2968#post2968

[content22207]

No quotation marks necessary. Some would argue that Ford ignition is an upgrade over OEM. I drove to/from church on it today no problem. If Byrne's Bosch ECU indeed is bad, he will be back on the road for less than $30 (with a lifetime warranty, redeemable any Autozone, until 10:00 at night, for a regularly stocked item, coast to coast).

Note that I have not modified a single thing to run Ford ignition -- merely plugged an adapter into the Bosch harness connector.

Bill Robertson
#5939

[DCUK Martin]

Interested in how this pans out. Ignition amp failures are rare.

[content22207]

Like I said, he reported at one point that an ice pick light was flashing on the negative side of the coil, in which case his ECU would of course have been fine. He also has reported the light glowing steady, in which case the ECU was not working (although the problem at that point could also have been caused by failure of distributor signals or power into the ECU). I don't really know what to expect -- I just want to be prepared for any contingency. I have spare distributors, but not spare ECU's -- or at least I didn't until I made a Bosch to Duraspark adapter....

Bill Robertson
#5939

[DCUK Martin]

Fair enough. Make sure to clean up the connectors on the ballast resistor and coil before fitting your non-oem amp.

[content22207]

I'm not starting with the ECU -- I'm starting with a timing light on the distributor lead wire (after splicing a solenoid trigger wire in the engine compartment).

Bill Robertson
#5939

[content22207]

I just returned from an ice cream run that included leaping into post fireworks traffic. Duraspark revs *PAST* 6,000 RPM no sweat.

Bill Robertson
#5939

[dmc6960]

Make sure the distributor cap is actually installed correctly and square...

I've recently done two caps which were an abnormal pain in the arse to fit on to the distributor. First one last year, took about an hour to get it to fit reaching under the venturi blindly. It should NOT have taken that long, I've done it in less than 5 minutes. Next one I did this year. However after an hour, all we were left with was a scuffed up cap, and a broken center button. So this time, I break out the spare cap I had from DMC with my Exhaust/Service kit (each came with a cap/rotor, so I had a spare). 1 minute and it was on perfect.

So what was the problem? A non-DMC vendor had supplied both caps. The seat on the caps were cut at a 45º angle, not square like the DMC one. Unless you completely remove all of the K-Jet stuff, there would be no way to squarely fit it onto the distributor. Last year I must have just gotten lucky. All tune-ups I assist with from now on must use DMC supplied parts.

[content22207]

Byrne's car is carbureted (his distributor is totally exposed).

Bill Robertson
#5939

[sean]

You said you don't know if his ignition ecu is bad, I have a good used one you guys can use to test with if you like.

[content22207]

The good news: Byrne's car is back on the road.

The bad news: his Bosch ignition module did not make the transition.
Nor did his Bosch spark plugs.
Nor did his .024" plug gaps.
Nor did his Bosch spark plug wires.
Nor did his Bosch blue coil.
Nor did his stock resistor grid.

Bill Robertson
#5939

[Bitsyncmaster]

The good news: Byrne's car is back on the road.

The bad news: his Bosch ignition module did not make the transition.
Nor did his Bosch spark plugs.
Nor did his .024" plug gaps.
Nor did his Bosch spark plug wires.
Nor did his Bosch blue coil.
Nor did his stock resistor grid.

Bill Robertson
#5939

So do you know what was the faulty component?

[Patrick C]

So do you know what was the faulty component?

Bosch, obviously. :)

[DCUK Martin]

Well done, Bill, you've "fixed" it be replacing everything. There's nothing like the brute force approach to problem solving :cowboy:

FWIW I've been fitting NGK plugs for some time now. I found the generic Bosch HT leads to be a bit "cheap".

[ramblinmike]

Bosch, obviously. :)

Uh-oh. Flame on!

On a serious note, I remember reading somewhere that increasing spark plug gap can cause spark arcing in the distributor cap. That is why later HEI distributors used larger caps when used with larger plug gaps. I'm wondering if the original plug gap had more to do with the need for the small space between contacts on the odd-fire distributor cap than any deficiencies with the Bosch ignition.

[content22207]

Well done, Bill, you've "fixed" it be replacing everything.

No, we fixed it first by replacing the module. Anyone who says Bosch ignition modules never go bad is delusional at best (why should Bosch be different from any other manufacturer's ignition modules, which do fail from time to time...). The difference now is Byrne has an adapter that will allow him to replace his Duraspark module with another one free of charge at any Autozone nationwide. Duraspark modules are stock items at all parts houses. Bosch ignition modules are not.

The remainder of his ignition upgrade was simply done to bring his DeLorean up to 21st century standards.

It never ceases to amaze me that the same people who champion upgrading DeLorean fuel delivery to later standards (EFI) persist hiding their heads in the sand about ignition.

DeLorean ignition was outdated when new. We looked up the plug gaps on various 1981 Ford products -- .05". Since Byrne is now running Ford plugs and a Ford ignition module, and real wire spark plug wires and a high winding coil, why shouldn't he run a Ford plug gap?

Bill Robertson
#5939

[content22207]

On a serious note, I remember reading somewhere that increasing spark plug gap can cause spark arcing in the distributor cap. That is why later HEI distributors used larger caps when used with larger plug gaps.

Nonsense. In Ford's case at least, taller distributor caps are an illusion -- the cap itself is the same height -- there's an adapter ring between it and the distributor body to house the magnetic pickup. Diameter of course was unchanged (a 1969 breaker point cap is the same diameter as a 1979 breakerless cap for the same engine).

GM HEI caps look so tall because they also house the ignition module and a capacitive coil.

Bill Robertson
#5939

[content22207]

So do you know what was the faulty component?

Engine started when we plugged in the Duraspark module. Engine did not start when then plugged the Bosch module back in. Since simply swapping out the module fixed his no start problem (timing light did not flash on the distributor lead wire with the Bosch module either), we surmised that the module was bad.

Why are people so convinced that Bosch ignition modules never fail? That is ignorant at best. What makes the ignition module any different from other Bosch components that fail? What makes the ignition module any different from other manufacturer's ignition modules that fail? What makes the ignition module any different from any other electronic device that fails (television, computer, DVD player, etc)?

I think you all are just pissed off because Byrne told European engineering to jump off a cliff and went American instead (his Pertronix coil and MSD plug wires are both Made in USA, BTW).

I have the Byrne's old module. I am going to cut off it's edge connector to make my own Bosch to Duraspark adapter. You are more than welcome to autopsy the rest of it if you want.

Duraspark modules only cost $25-$28, are stock items at all parts houses, and come with lifetime warranties if necessary -- I see no reason to mess with Byne's old module any further than to cut off the one component that does have utility for me.

Bill Robertson
#5939

[DCUK Martin]

Bill, will you ever "get it"?


Anyone who says Bosch ignition modules never go bad is delusional at best (why should Bosch be different from any other manufacturer's ignition modules, which do fail from time to time...).



I don't think anyone ever said "they never fail". I've supplied a DeLorean module for use in a GTA because theirs live in the engine compartment and get much hotter. The fact remains it's a very rare failure.




The difference now is Byrne has an adapter that will allow him to replace his Duraspark module with another one free of charge at any Autozone nationwide. Duraspark modules are stock items at all parts houses. Bosch ignition modules are not.



Given he is in the n'th fraction of a percent of owners whose ignition module has failed, it's a very, very slight selling point (and you were offered a working spare direct-swap Bosch unit...)




The remainder of his ignition upgrade was simply done to bring his DeLorean up to 21st century standards.

It never ceases to amaze me that the same people who champion upgrading DeLorean fuel delivery to later standards (EFI) persist hiding their heads in the sand about ignition.



So you upgraded him to coil-on-plug and fully mapped ignition did you? No, you fitted equally old technology and changed things based on your own erroneous beliefs about plug gaps.



DeLorean ignition was outdated when new. We looked up the plug gaps on various 1981 Ford products -- .05".


PLEASE, explain to everyone why a plug gap has anything at all to do with the "age" of the technology?

[DCUK Martin]

I think you all are just pissed off because Byrne told European engineering to jump off a cliff and went American instead (his Pertronix coil and MSD plug wires are both Made in USA, BTW).

Speaking for myself, it's your "selling" of this as a "better" solution. I'm sure you'll continue to crow about it and rabbit on about plug gaps whatever is said here but let's get it on the record: The stock ignition system, when working properly is very reliable and powerful enough to light up the spark on my turbo engines running over 14psi of boost (using NGK BP7EFVS turbo plugs).

[content22207]

... your own erroneous beliefs about plug gaps.



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Bill Robertson
#5939

[content22207]

Speaking for myself....

Speaking for myself, the stock ignition system is crap.

In my opinion.

Bill Robertson
#5939

[content22207]

Just so there is no confusion: only putting a high winding coil on a DeLorean alone may not be sufficient to jump a .05" plug gap. Ford ran 10.5 volts into its inductive coils. Secondary voltage is of course a multiple of primary voltage -- more primary voltage produces more secondary voltage. A stock DeLorean resistor grid only produces 6-8 volts into the coil, IIRC. I have wired mine in parallel, which produces 12.5 volts when the alternator is charging:
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BTW: did anyone notice that SAE paper found increased combustion efficiency from increased secondary voltage (Pages 6-7) as well as increased plug gap?

Bill Robertson
#5939

[ramblinmike]

Nonsense. In Ford's case at least, taller distributor caps are an illusion -- the cap itself is the same height -- there's an adapter ring between it and the distributor body to house the magnetic pickup. Diameter of course was unchanged (a 1969 breaker point cap is the same diameter as a 1979 breakerless cap for the same engine).

Not true. The breakerless caps are significantly larger. It is true that an adapter ring was used since the aluminum distributor housing is basically unchanged. See image below.

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I'm in the middle of gathering parts for a duraspark swap on my '66 Mustang. The cap on the left is form the duraspark distributor from a '77 302 Mustang that I plan on using. The cap on the right is the original Ford points cap. Notice the size difference.

[Bitsyncmaster]

I think the original ECU is pretty reliable but like all electronics if some malfunction with the power source or the load current is run beyond the design it may fail.

So an alternator that goes bad and starts putting 16 to 18 volts into the unit or putting a low resistance coil without modifying the resistors can overstress the design.

Bad components will usually show up a failure in the first few hours of operation.

[content22207]

You are mixing apples and oranges. Autolite distributors of the 1960's were holdover designs that predated Ford's purchase of the company. In the 1970's, Ford totally redesigned distributors manufactured under the Motorcraft moniker. The caps differ because you're dealing with two totally different distributor designs that just happen to share common shaft and drive gear sizes.

As soon as batteries recharge in The World's Cheapest Digital Camera I will photograph a 1969 460 distributor cap (breaker point, socket terminals) and a 1979 460 distributor cap (Duraspark, HEI terminals), both from Ford designed Motorcraft distributors.

Is your Autolite distributor worn out (they were subject to premature wear, which is one reason Ford redesigned them)? If not, why not simply stick a Pertronix Ignitor unit where the breaker points used to be? I'm running one in my 1969 Lincoln motor with excellent results, and I have one in my Church's 1977 International Harvester bus. Both are attached to Pertronix coils with full charging voltage.

Bill Robertson
#5939

[content22207]

never mind the batteries (i think they're dying anyway) -- i am on the phone with a friend of mine as we speak and he is explaining the origin of the larger diameter distributor caps ford went to in the 1970s -- they are designed to increase spark duration. the rotor button is physically wider than a 1960s rotor button to increase spark duration. the distributor cap is bigger to accomodate the larger rotor button.

my friend also thinks you all are nuts. of course he thinks anyone who would choose a delorean over a ford is nuts.

[stevedmc]

So an alternator that goes bad and starts putting 16 to 18 volts into the unit or putting a low resistance coil without modifying the resistors can overstress the design.

Maybe I am missing something but if you alternator is putting out 16 to 18 volts you should pull into the nearest Autozone and replace the dang thing.

[ramblinmike]

Is your Autolite distributor worn out (they were subject to premature wear, which is one reason Ford redesigned them)? If not, why not simply stick a Pertronix Ignitor unit where the breaker points used to be? I'm running one in my 1969 Lincoln motor with excellent results, and I have one in my Church's 1977 International Harvester bus. Both are attached to Pertronix coils with full charging voltage.

Bill Robertson
#5939

The original Autolite is fine. I'm gong with the Duraspark for several reasons. First, the availability of a replacement unit at any parts house anywhere. I drive the car often and the reassurance of knowing I can get back on the road quickly if something happens is worth it. Basically the same reason you're contemplating building yourself another Duraspark-Bosh adapter just in case. Second, the motor is a completely stock 1966 289. Any electronic ignition would be a major upgrade for my 45-year-old motor. Third, I already own most o the parts from previous projects that I've stashed away. Free is good. It is much easier to get a $20-30 part purchase for missing pieces past my wife than a new petronix unit. I've looked into it. Even if I thought she'd approve the petronix purchase I'd still be without local off-the-shelf replacement options. The aforementioned lifetime warranty is also a good thing.

I don't know if the rotor tip size is different between the old points setup and the Duraspark. Ill look in the morning. I'd be surprised that the size is that much different to completely account for the drastic change in cap diameter.

Your friend is right about all of us being nuts. I think that all car guys are nuts simply because everything will eventually break. I don't care if it's a DMC, Ford, whatever. It will eventually screw up. I guess that's the fun isn't it?

[Bitsyncmaster]

Maybe I am missing something but if you alternator is putting out 16 to 18 volts you should pull into the nearest Autozone and replace the dang thing.

If you ECU has not fried by then, yes you should shut it down immediately. Thankfully over charging is a very rare failure.

[content22207]

Apologies for the delayed response -- an emergency came up yesterday afternoon (a lady from church, not mine).

I'm getting ready for church so I can't take my distributor caps off now, but in the meantime here's a distributor cap for an AMC Prestolite distributor which also used Duraspark ignition that is not worlds removed from our Bosch caps:

http://i.ebayimg.com/22/!CCfPzy!B2k~$(KGrHqV,!jcE0DWlPYooBNLR)vCmz!~~0_12. JPG

Bill Robertson
#5939

[content22207]

Flat measurement across a breaker point 460 rotor blade: .345 inches
Flat measurement across a Duraspark 460 rotor blade: .640 inches
(Actual circumferencial length of each rotor blade is of course slightly more because they have curved shapes).

Ford obviously decided to nearly double the length of secondary ignition discharge in their distributor redesign.

The bigger distributor cap to prevent cross firing is probably an old wives tale.

Bill Robertson
#5939

[content22207]

Flat measurement across a PRV rotor blade: .435 inches

ID breaker point 460 distributor cap: ~3.375"
ID PRV distributor cap: ~3.1875"

Later tonight I will calculate PRV secondary duration versus 460.

Bill Robertson
#5939