Rough idle and other problems... any thoughts?

[djrobinfo]

Ok so my D has been sitting for a few years and of course it wouldn't start. I cleaned out the gas tank and replaced fuel filter screen in tank. It still wouldn't start. I ended up needed a new rpm relay so I put a new one it. And the car started but the battery would drain and the car would die. I ended up having to replace the battery light in the dash. That fixed that problem. So now the car is running and idling very rough and it has been so long since I have ran it that I don't remember how shaky it was before. I know it is more shaky than it should be but I don't know by how much. Also I get very little power when the car is in gear. Plus it is also much more shaky when in gear. I believe the some of the fuel injectors and dirty / semi clogged. What I want to do first is change the oil, then run fuel system cleaner through it and see how much of a difference it makes. If I need to I will then take a look at the fuel injectors. But in the mean time I took a video of the car running so you all could see how much it is shaking and let me know how bad you think it is. Please take a look at the video and let me know what you think.

http://www.youtube.com/watch?v=mz76kUzkeTw

[Jack]

http://fc06.deviantart.net/fs24/i/2007/365/4/8/Shake_shake_shake_senora_by_LilithDash.jpg
Are all plugs firing?
Also have you pulled the injectors to test the spray pattern?

[DeLorean03]

This is just me talking here:

That car needs a tune up. Plugs, plug wires, cap and rotor, and possibly cleaning of/changing the injectors. Is there a thread detailing the history of this car? Not trying to insult you, just saying here, I sure hope multi-year old fuel is not in that car.

[Bitsyncmaster]

That is a pretty consistant skip. Sounds like a bank of cylinders are not working. I would suggest you pull the injectors and see if all six are working.

[NightFlyer]

I'll tell you what Dave Swingle told me when I was working out this EXACT issue with my D - "FUEL, FUEL, FUEL, - it's almost always FUEL with these cars."

Dave was dead on!

My engine was running exactly like yours is in the video.

The fuel injector test is vital to figuring out exactly where the problem is. Remember that you need to run the test multiple times to determine exactly where the problem is, as it could be with the the fuel injector(s), the fuel distributor, or even a combination of both.

See the 'How To' for a reference:

http://dmctalk.org/showthread.php?46-How-To-Test-fuel-injector-spray-patterns

In my case, two injectors/cylinders on the right-hand bank weren't getting hardly any fuel from the fuel distributor. Replacing the distributor with a rebuilt one from DMCH (via DMC-Midwest) solved all my problems.

Best of luck!

[djrobinfo]

I'll tell you what Dave Swingle told me when I was working out this EXACT issue with my D - "FUEL, FUEL, FUEL, - it's almost always FUEL with these cars."

Dave was dead on!

My engine was running exactly like yours is in the video.

The fuel injector test is vital to figuring out exactly where the problem is. Remember that you need to run the test multiple times to determine exactly where the problem is, as it could be with the the fuel injector(s), the fuel distributor, or even a combination of both.

See the 'How To' for a reference:

http://dmctalk.org/showthread.php?46-How-To-Test-fuel-injector-spray-patterns

In my case, two injectors/cylinders on the right-hand bank weren't getting hardly any fuel from the fuel distributor. Replacing the distributor with a rebuilt one from DMCH (via DMC-Midwest) solved all my problems.

Best of luck!


Thats pretty much what I was thinking. Yes the fuel in the tank was in there for a few years and yeas it was very bad. However, before I started the car after it sat for a few years I did a full tank clean out. The distributor was replaced by DMCH maybe 8 years ago and the car has had very little use since then. I realize that doesn't mean there is not something wrong with it. But I do think it is less likely to be the distributor as it is the newest part on the car. (i think they also replaced the accumulator) I am and have been thinking it is the injectors, I just wanted a second opinion. I will try testing/cleaning the injectors and see how it goes. I will let you all know. Thanks

[NightFlyer]

Thats pretty much what I was thinking. Yes the fuel in the tank was in there for a few years and yeas it was very bad. However, before I started the car after it sat for a few years I did a full tank clean out. The distributor was replaced by DMCH maybe 8 years ago and the car has had very little use since then. I realize that doesn't mean there is not something wrong with it. But I do think it is less likely to be the distributor as it is the newest part on the car. (i think they also replaced the accumulator) I am and have been thinking it is the injectors, I just wanted a second opinion. I will try testing/cleaning the injectors and see how it goes. I will let you all know. Thanks

Just because the distributor was previously replaced, don't automatically rule it out of the equation. Ethanol has a way of deteriorating the thin metal diaphragm/plate between the two halves. If you do end up narrowing the problem down to the fuel distributor, there is a rebuild kit available that includes a new diaphragm/plate, if you're willing to tackle a rebuild yourself.

The rebuild kits can be obtained from the eBay seller 'cis-jetronic' for about $80-$90.

[DMCMW Dave]

. The distributor was replaced by DMCH maybe 8 years ago and the car has had very little use since then.

Sitting with the same gas in it for 8 years is not new. The flow test will tell you if it's injectors or distributor. Or both.

[djrobinfo]

I realize that doesn't mean there is not something wrong with it. But I do think it is less likely to be the distributor

I just checked the injectors well 5 of them at least. The last one looks like a bitch to get to. I will check it in the morning. Anyway, the 5 I checked were good. Again I'm not ruling out the distributor but I'm going to check the spark plugs before I check the distributor. What do you all think?

[NightFlyer]

I just checked the injectors well 5 of them at least. The last one looks like a bitch to get to. I will check it in the morning. Anyway, the 5 I checked were good. Again I'm not ruling out the distributor but I'm going to check the spark plugs before I check the distributor. What do you all think?

Could possibly be an ignition issue, however, I don't believe so - not with the way it was running in the video. If it was ignition related, then you should have noticed the smell of un-combusted fuel being dumped into the exhaust, and upon heat up of the exhaust, some backfiring occurring. Based on the video, I don't get the impression that there was anything unusual about the exhaust.

My money's still on fuel delivery.

When you performed the injector test, did all the injectors yield an equal amount of fuel?

[DMCMW Dave]

I just checked the injectors well 5 of them at least. The last one looks like a bitch to get to. I will check it in the morning. Anyway, the 5 I checked were good. Again I'm not ruling out the distributor but I'm going to check the spark plugs before I check the distributor. What do you all think?

How did you check them? If one was still in place and you followed the process, you have flooded that cylinder.

You really need to do this with all 6 out of the engine so you can test the flow at various flow rates including wide open.

[djrobinfo]

How did you check them? If one was still in place and you followed the process, you have flooded that cylinder.

You really need to do this with all 6 out of the engine so you can test the flow at various flow rates including wide open.

I did them one at a time. I am going to try again tomorrow and I will do it with all 6 out at the same time.

[djrobinfo]

Could possibly be an ignition issue, however, I don't believe so - not with the way it was running in the video. If it was ignition related, then you should have noticed the smell of un-combusted fuel being dumped into the exhaust, and upon heat up of the exhaust, some backfiring occurring. Based on the video, I don't get the impression that there was anything unusual about the exhaust.

My money's still on fuel delivery.

When you performed the injector test, did all the injectors yield an equal amount of fuel?

Yeah I guess your right on that one. I don't smell un-combusted fuel and I'm not getting any backfire.

Yes it seemed that they were all getting the same amount of fuel but I tested them one at a time. I am going to test them all together tomorrow.

[djrobinfo]

Another thing I just though about. After I cleaned the gas tank I added 5 gallons of gas and about half a bottle of HEET water remover just in case I missed any moisture in the tank. After that I was having this low power problem so I was thinking the injectors could be dirty so I added another 5 gallons of gas and a bottle of Lucas upper cylinder lubricant and injector cleaner. Do you think this could be an issue? do I have to much additive? should I add more gas?

[NightFlyer]

How did you check them? If one was still in place and you followed the process, you have flooded that cylinder.

You really need to do this with all 6 out of the engine so you can test the flow at various flow rates including wide open.

I was wondering the same thing myself, but thought that maybe he disconnected the injector he didn't pull and plugged that line somehow - although I'm thinking that attempting to do it this way would be bad for the fuel distributor.

Yes, you really need to do all 6 at once and run multiple tests at different levels of throttle in order to compare the flow rate of the injectors. Start with a couple wide open tests, then a couple 50% tests, then a couple 20% tests, then a couple barely open tests. You also need to run the test after changing around the fuel distributor port/injector combinations in order to determine the status of the fuel distributor (or disconnect all the injectors and run the test with just the hoses, as Ron pointed out in the 'how to' thread).

There's no short cut around this - trust me, I know.

If you flooded the port of the injector that you didn't pull, maybe you can get a siphon hose down the bung of that cylinder that you flooded upon pulling the injector and attempt to get as much fuel out of there as you can before attempting a start-up.

[NightFlyer]

Another thing I just though about. After I cleaned the gas tank I added 5 gallons of gas and about half a bottle of HEET water remover just in case I missed any moisture in the tank. After that I was having this low power problem so I was thinking the injectors could be dirty so I added another 5 gallons of gas and a bottle of Lucas upper cylinder lubricant and injector cleaner. Do you think this could be an issue? do I have to much additive? should I add more gas?

I don't think a bottle of HEET and a bottle of Lucas upper cylinder lubricant would effect performance to the level that you're experiencing. Personally, I think that most of those types of products are voodoo and an ineffective waste of money.

But, if you're really concerned about what you currently have in the tank, you could siphon the tank as low as you can and refill with ethanol free gas. You can use this website to find a station near you that sells it:

http://pure-gas.org/

Pure ethanol free gas is going to do wonders vs any of the voodoo additives that you can buy.

[djrobinfo]

.

If you flooded the port of the injector that you didn't pull, maybe you can get a siphon hose down the bung of that cylinder that you flooded upon pulling the injector and attempt to get as much fuel out of there as you can before attempting a start-up.

If I did flood it, what will happen if I try to start the car without getting the fuel out of the cylinder? Will the fuel dissipate over night?

[NightFlyer]

If I did flood it, what will happen if I try to start the car without getting the fuel out of the cylinder? Will the fuel dissipate over night?

It's honestly not a huge deal.

Worst thing I see happening is that you foul the plug out and push a bunch of raw un-combusted fuel into the exhaust (which contributes to plugging up the catalytic converter).

[djrobinfo]

I don't know what I did but the car is running right! I started it up and revved it a little and when I let off I noticed it didn't seem to be so shaky so I put it in gear and gave it some gas and it was just fine! I can't believe it. I guess checking/ testing the injectors must have knocked something lose!

[NightFlyer]

WOW - rarely does anyone get so lucky in the world of DeLorean's :biggrin:

But that's awesome!!! Glad everything worked out for you :thumbup:

[David T]

My guess is the plunger was sticking in the fuel regulator and you were running way too rich. It unstuck and now you are OK. Old, stale fuel is about the biggest problem for old Deloreans followed closely by old, corrosive brake fluid. Next is old tires, batteries, door seals, headliners, and struts. Modern fuel does not store well and can do a lot of damage. Now that you have a real concoction in the fuel tank I would run it down as low as possible and refill with fresh. After 8 years of sitting I would expect the clutch and brakes to start leaking once you start using the car again. Keep an eye on the fluid levels.
David Teitelbaum

[djrobinfo]

My guess is the plunger was sticking in the fuel regulator and you were running way too rich. It unstuck and now you are OK. Old, stale fuel is about the biggest problem for old Deloreans followed closely by old, corrosive brake fluid. Next is old tires, batteries, door seals, headliners, and struts. Modern fuel does not store well and can do a lot of damage. Now that you have a real concoction in the fuel tank I would run it down as low as possible and refill with fresh. After 8 years of sitting I would expect the clutch and brakes to start leaking once you start using the car again. Keep an eye on the fluid levels.
David Teitelbaum

Thanks David. I will keep that in mind. I have only been on this site for a week or 2 now any you have already helped me out quite a bit. Thanks again!

[NightFlyer]

I'm going to have to disagree with David here - no way that a sticky plunger in the FD would have caused it to run as in your posted video.

[krs09]

My rough running issue will not go away. I feel like im in way over my head. When it finally does start (takes a few cranks - intermittenly) it will run real rough and giving it gas it just falls on its face and stumbles. I tested the spray patterns with the injectors and wasnt very happy so I replace all the injectors. I tested the fuel pressure by hooking up the gauge and jumping the rpm relay and found i have a steady 69psi coming from the pump. My rest pressure is bad but not sure that would cause my running issue. I know its vauge but any thoughts on what to try? I think my CPR is bad but just not sure. Any sure fire ways to test it? I dying over hear! Any help would be great. Any other questions to help you get an idea let me know. The only things I have not replaced on the car is the CPR, distrubtior, ISM, CSV, frequency valve and everything else is new. HELP!:bawling::bawling::bawling:

[krs09]

O and when it did start it shot so much white smoke I almost pooped my pants. I turned it right off and could see the smoke just sitting at the tail pipes. What would cause plums of white smoke out of nowhere? Ahhh!:bawling::bawling::bawling:

[DeLorean03]

To Krs09:

You need to get one of these if you're going to want to properly diagnose the system (I know you said you have a gauge, is it KJet specific...?):

http://www.toolfetch.com/tool-aid-53800-cis-k-jetronic-fuel-injectionpressure-tester.html?cvsfa=2865&cvsfe=2&cvsfhu=54413533383030&gclid=CIWR27aPwbkCFalcMgod7AgAxg

Does the car run smoothly and then start all of these issues you stated when it warms up? Long explanation short, the CPR runs the car richer when it is first started. As the engine warms up, the CPR leans out the fuel mixture. Way to know for sure: hook those gauges in that link provided and measure the control pressure.

You said you have white smoke coming out of your exhaust. That can either be coolant or fuel. Since you have had your engine rebuilt, I'd say it's excess fuel - better than a bad head gasket ;).

Does your car "clear up" at all - or does it just run badly all the time - cold, warm, and hot? 69 PSI is a bit on the low side; it's not excessively low, but it's not 75psi+ either, which is what I have always measured on my fuel system.

[Jack]

Have you tried "resetting" the mix?
I believe Ron has good info on this.
If I remember right, you jump the RPM relay same as if your testing the injectors.
Pull one or all the injectors.
Turn the mixture screw until the injectors begin to dispense fuel.
Then turn back until it/they stop.
THIS IS NOT THE FINAL MIX.
Just a good starting point to fine tune with a dwell once you get the car running.

Of course vacuum and everything else in the system needs to be correct for the dwell meter to be useful.


O and when it did start it shot so much white smoke I almost pooped my pants. I turned it right off and could see the smoke just sitting at the tail pipes. What would cause plums of white smoke out of nowhere? Ahhh!:bawling::bawling::bawling:

[krs09]

To Krs09:

You need to get one of these if you're going to want to properly diagnose the system (I know you said you have a gauge, is it KJet specific...?):

http://www.toolfetch.com/tool-aid-53800-cis-k-jetronic-fuel-injectionpressure-tester.html?cvsfa=2865&cvsfe=2&cvsfhu=54413533383030&gclid=CIWR27aPwbkCFalcMgod7AgAxg

Does the car run smoothly and then start all of these issues you stated when it warms up? Long explanation short, the CPR runs the car richer when it is first started. As the engine warms up, the CPR leans out the fuel mixture. Way to know for sure: hook those gauges in that link provided and measure the control pressure.

You said you have white smoke coming out of your exhaust. That can either be coolant or fuel. Since you have had your engine rebuilt, I'd say it's excess fuel - better than a bad head gasket ;).

Does your car "clear up" at all - or does it just run badly all the time - cold, warm, and hot? 69 PSI is a bit on the low side; it's not excessively low, but it's not 75psi+ either, which is what I have always measured on my fuel system.

I do have a bosh pressure gauge (t33865) although that one is a bit cheaper. It does run rough all the time (start,hot,cold) but after the rebuilt it did run smooth but had a high idle (i did figure that out) and this came out of nowhere. It started to run rough a little and stall, now it almost always stalls out on the first 2-3 starts, on the 4th time I can hear the ISM save it and just bearly keep it running. I do hope that smoke was excessive gas (I did try start it a few times with no avail before the smoke came out). Hate to sound dumb but one more time on testing the CPR. I have read the volvo k-jet book and all signs seem to point to the CPR but it seemed to work just fine 2months ago. Thanks. Keep it coming.

[krs09]

Have you tried "resetting" the mix?
I believe Ron has good info on this.
If I remember right, you jump the RPM relay same as if your testing the injectors.
Pull one or all the injectors.
Turn the mixture screw until the injectors begin to dispense fuel.
Then turn back until it/they stop.
THIS IS NOT THE FINAL MIX.
Just a good starting point to fine tune with a dwell once you get the car running.

Of course vacuum and everything else in the system needs to be correct for the dwell meter to be useful.

That is one thing. I have never been able to get a good dwell reading (its always nowhere near where it needs to be and never "sweeps"). Is that a good way to get a base mix without using a Dwell meter??:headscratch:

[DeLorean03]

I do have a bosh pressure gauge (t33865) although that one is a bit cheaper.

Can you provide me a link for this gauge? I tried both Bosch and Bosh with that t-number, and Goggle gave me nothing ....:hmm:

You said you fixed the high idle - just to cover all bases - how was that rectified?

The fact that you stated earlier that if you give the car gas it stumbles and wants to die - that to me says starved for fuel. Also, a weak fuel pump or blockage in a fuel line could be giving you fuel pressure readings below 70psi ... you know for sure your fuel delivery at the front of the car is good and solid - no kinks in any rubber lines at the fuel pump or in the fuel tank?

Can your fuel pressure gauges read control pressure? If so, time to test it. It is in the workshop manual: page D:02:01 - step 3a. When you first measure it, it will read low. Wait a very small (1-2 minutes), and your control pressure should be in the 3.4 - 3.8 bar per the manual.

[Jack]

Ahh so you are probably out of range.

I didnt realize your car was running at all sorry about that.
So you DONT need to do the reset.

Is your O2 sensor "good"?
There is a default the dwell meter should read when the mix is set outside of range.
Do you remember where the reading/needle was stationary at?


That is one thing. I have never been able to get a good dwell reading (its always nowhere near where it needs to be and never "sweeps"). Is that a good way to get a base mix without using a Dwell meter??:headscratch:

[krs09]

Can you provide me a link for this gauge? I tried both Bosch and Bosh with that t-number, and Goggle gave me nothing ....:hmm:

You said you fixed the high idle - just to cover all bases - how was that rectified?

The fact that you stated earlier that if you give the car gas it stumbles and wants to die - that to me says starved for fuel. Also, a weak fuel pump or blockage in a fuel line could be giving you fuel pressure readings below 70psi ... you know for sure your fuel delivery at the front of the car is good and solid - no kinks in any rubber lines at the fuel pump or in the fuel tank?

Can your fuel pressure gauges read control pressure? If so, time to test it. It is in the workshop manual: page D:02:01 - step 3a. When you first measure it, it will read low. Wait a very small (1-2 minutes), and your control pressure should be in the 3.4 - 3.8 bar per the manual.

The fuel gauge Im using is -Tool Aid 33865 C.I.S. K-Jetronic Fuel Injection Tester with Case. I had to jump the thermister behind the driver seat to bring down the idle. I did check the pump at the tank (new) and the hoses all looked good and have SS bradied lines from the distrubitor.

[DeLorean03]

Excellent - good stuff all around with that answer. Test your control pressure and see if it reads as the specs in the workshop manual. Let us know what you find, and we'll see where we go from there.

[krs09]

Ahh so you are probably out of range.

I didnt realize your car was running at all sorry about that.
So you DONT need to do the reset.

Is your O2 sensor "good"?
There is a default the dwell meter should read when the mix is set outside of range.
Do you remember where the reading/needle was stationary at?

I think it sat at the 5-10 mark and would not move not matter where I set the screw.

[Bitsyncmaster]

I think it sat at the 5-10 mark and would not move not matter where I set the screw.

Not a common problem but the lambda ECU may be faulty.

[krs09]

Excellent - good stuff all around with that answer. Test your control pressure and see if it reads as the specs in the workshop manual. Let us know what you find, and we'll see where we go from there.

So I just got done doing a little more testing and heres what I found. Using the jumper for the rpm relay I had 69psi steady from the pump (primary pressure)so "per the manual" I shut off the fuel pump and switched the valve to the CPR (control pressure) and had a steady 32psi and it did not move at all over a 3min period. So Im really not sure if that's good news (CPR is good) or not. Any advice?? :confused0:

O and I did try the same test without turning off the pump and had to same results.. Just figured I throw that out there

[Bitsyncmaster]

So I just got done doing a little more testing and heres what I found. Using the jumper for the rpm relay I had 69psi steady from the pump (primary pressure)so "per the manual" I shut off the fuel pump and switched the valve to the CPR (control pressure) and had a steady 32psi and it did not move at all over a 3min period. So Im really not sure if that's good news (CPR is good) or not. Any advice?? :confused0:

O and I did try the same test without turning off the pump and had to same results.. Just figured I throw that out there

I check control pressure with the gauge connected (valve open) and the engine running at idle cold (RPM relay installed). When the engine is cold you get 20 to 30 PSI at first and as it warms up it climbs to about 50 PSI.

I would guess checking the CPR pressure without the engine running and RPM relay jumpered would give you one accurate reading if you were trying to adjust the CPR calibration. Without the RPM relay, you would not get the CPR heater running so it should hold that pressure until the temperature changes or you loose fuel pump pressure.

[dn010]

With all these tests and recommendations for checking the fuel system - have you actually confirmed your ignition system is in good working order; plugs look good - cylinders are dry when you remove them, tested the wires to see if they were getting spark, etc- all that fun stuff? You can test and replace everything in the fuel system, but what good does it do if you didn't confirm that you can actually make the delivered fuel explode...


When I had K Jet, I had an issue where I ran the engine and it had nothing but a huge billowing white cloud of smoke behind it and raw fuel pouring out of the exhaust pipes. - That turned out to be a bad fuel distributor.

These SECOND time I had issues with K Jet, I had some white smoke (smelled like fuel too) and a dribble of fuel coming from the pipes, terrible idle and it would hardly run. Took all the plugs out - 2 of the cylinders were wet, the rest dry. Ran the engine and tested each spark wire with a timing light - and one was bad. Replaced plugs, ran the engine and indirectly hit the wiring harness behind the engine while I was doing something else - it suddenly ran fine. So I shook the harness it would run fine - I'd let go of it and it went back to rough idle. Turned out I missed hooking up my main ground buss to the engine and my bulk head connectors were corroded. Fixing both + a new cap & rotor fixed this lean running issue and no spark problem.

Good luck, I know how frustrating pin pointing this can be!

[krs09]

With all these tests and recommendations for checking the fuel system - have you actually confirmed your ignition system is in good working order; plugs look good - cylinders are dry when you remove them, tested the wires to see if they were getting spark, etc- all that fun stuff? You can test and replace everything in the fuel system, but what good does it do if you didn't confirm that you can actually make the delivered fuel explode...

All that stuff is brand new. I rebuilt the engine a few months ago and replaced just about everything (plugs,wires,cap,injectors,fuel lines ect.). Whats really killing me is that it ran fine for a while (a little high idle but was fixed by jumping the thermister) then out of nowhere it stumbles all over the place and stalls on the first 2-3 starts before staying running (shitty but running) .. Anybody know a way of setting the dwell without using a meter? ... I really hate to send my car to a vendor for diag and repair (due to empty pockets and I like to learn as much as I can on my D) but I may not have a choice. For the first time Im really fustrated with her. Now it may be a dicision of PJ Grady or DPI. Dammit!

[dn010]

Just because it was replaced or new, doesn't mean it works :biggrin: so for laughs I'd at least test the wires with a timing light and pull the plugs to see what they & cylinders look like; takes about 5 maybe 10 minutes and then you can rule those out. As for setting the dwell, Jack posted the steps on page 3, might get you close if you have no idea where its set now.

[krs09]

So I was able to play with the car over the weekend and heres what I got. My first goal was to do the base mix by pulling 3 injectors from the right side of the engine (the easy ones) and put them in glass jars. It looks like my mix was way off because I had to turn the screw 2 ½ full turns (to the right I believe) before the injectors started to dispense fuel. One issue was one of the injectors started much earlier than the other 2. So after reinstalling all 3 injectors I started the car and it ran a 1000% better, started right up-had a good steady idle and pressing on the gas did not cause it to fall on its face and stumble but I did have a lot of white smoke coming out of the right tail pipe. After seeing the smoke I had a feeling it may be too much gas going into the cylinder on the one injector that looked slightly faulty so I took it back out and replaced it with a new one I had laying around.After reinstalling the new injector the car ran a little better and white smoke was gone! ALL good news for the day really (not perfect but waaay better)

The only issue I came across was after revving the engine and warming it up the car started to idle hunt pretty good, not as bad as ive had it before but it was hunting. I can only guess thats because I set the base mix when the engine was cold and not warmed up? Not sure.

Also after the warm up and the hunting began I had a bad surge in power. My oil pressure and volt gauge would drop and rise in sequence with the idle hunt. My door lights (leds) and my cooling fans (DPMW upgraded unit) would do the same surging (dimming and losing power). This being after the car sat on a tender for days and had a full battery when I started the process. What could cause something like that. Any other tips or tricks to make sure im on the right path.

Thanks Jack for the setting trick, I would still be in bad shape if not for that:thumbup:

[Jack]

Awesome :biggrin:
Ron deserves the credit on that one, I believe he taught me that trick :)
You pick up so many tips its hard to keep it all straight.

Sounds like you were able to knock out some issues.

My idle hunts some if I cut off my A/c but is very stable with A/C on.

As for the loss of power, once you know your mix is great/good.
And "everything" else is good.
You can adjust the throttle.
Even though the ICU keeps the RPMS at 750ish +/- 25
You can adjust the throttle screw to keep the RPMS at the top of that range.
This will help with power loss at idle when warm.
It will open the butterfly valves slightly.

When I adjust my throttle:
1. I back the screws almost all the way out, both of them.
2. Then I make sure the spring is able to fully close the butterflys. You may have to adjust the linkage under the spring. (I had to adjust mine a little bit longer.) You can remove the "air horn" pretty easily and quickly to verify the butterfly are closing correctly. Since your engine was rebuilt I would think your butterly valve springs are in good shape. Then I reconnect everything.
3. I back the lower throttle screw in until I you see the arm start to move. Then I manually press the idle micro switch and check the RPM reading using a meter. If it good I lock it down. If its hunting badly I adjust the screw very very slowly until I hit the upper 750 limit of the ICU. Test it a few time by revving the engine making sure its good.
4. Then I turn the engine off.
I back the upper screw in for the idle micro switch and listen for the click that it was tripped. Turn the screw about 1/2-1 full turn more.
5. Pull the thottle and make sure every-time you release it you hear a click at the very end of the linkage travel. Lock it down.
6. Test drive 15+ minutes.

I repeat 3-6 if things act differently on the road. I just pull onto the shoulder and do minor adjustments to those two screws.

[Bitsyncmaster]

You need to fine tune the mixture with a dwell meter for book values. Then leave it there. If you still get a hunting idle look for problems elsewhere. To many people adjust mixture to get the best idle. Then they get poor performance when driving on the road.

[krs09]

Thanks for all the tips guys. I will have to play with the throttle once this is mostly settled. It will be a little harder since my tach is inop but we'll make it work.. Any ideas on the whole surging issue?? :eek7:

[DeLorean03]

Any ideas on the whole surging issue?? :eek7:

Too many to count :P.

Most of the time, it leads back to the fuel adjustment being too rich.

[krs09]

You got that right! Really trying to sift through all the shit. May be a stupid question but could it be a faulty alternator? Its one of the only things I have not replaced. I did test it, I got 12.5 volts fromt the battery (with car off) and 13.5 with the car running.

[Bitsyncmaster]

You got that right! Really trying to sift through all the shit. May be a stupid question but could it be a faulty alternator? Its one of the only things I have not replaced. I did test it, I got 12.5 volts fromt the battery (with car off) and 13.5 with the car running.

Sounds like it is working but nomaly a cold alternator will produce 14.5 volts. When it gets hot the voltage will drop.