Still losing spark (solved )

[DAV!D]

After having working through all the problems I've had in the last few weeks I still have a issues with losing spark. I thought I had it fixed with a new ground but the problem remains, but it seems to come and go.

What I'm doing, is hooking up a timing light and wiring the trigger on. This lets me see if I have fire.

When I first turn on the ignition switch, I get the little buzz sound. When I turn the key, I get fire but then it stops and as the engine turns over I get no more fire. However sometimes, not always it gets fire again as I release the key.

It seems to do this most often if the van is cold. Once it's been run for a bit, it will usually fire and start again.

What is worse is the problem seems to come and go. Might do it one day and then work fine for a week.

What I've done..

I've tried 3 different coils
I've swapped distributors
I've cleaned all my grounds and added a new ground strap.
When I check the voltage at the Hal sender plug, with the key on I'm over 10v was 11.something volts.

I've also manually activated the Hal unit or what ever the thing is that buzzes, by using a test light to the center pin and touching ground.

I'm not sure what else or how else to test anything I haven't already. Anyone have any ideas, because I can't keep having it go out like this.


**update**

I seemed to have narrowed it down, to most of the time being able to unplug the ECU and plug it back in. This usually allows me to get spark. However the issue is getting worse and it's happening pretty much every day and at least 50% of my start attempts.

Other things I've done..

Replaced the coil, rotor, cap.
Used a test jumper from the electrical box "hot" wire to the +15 on the coil.
Begged the van to start and cursed it when it didn't.
I'm still debating if lit match in gas tank will resolve the issue.


Update again..

Swapped out the ECU the engine now idles at first start and has started every time "so far". I still have a cold/warm start sputter/miss, but I'm hoping that will be resolved by changing the rubber gasket at the throttle body.

Will have to give it a few days before I know for 100% that the new ECU fixed the no spark issue. I still plan to order a new ignition switch.

Last update..

Made it a week with out a single loss of spark, so I'm calling it solved as being the replacement ECU fixed it.
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86 Syncro Build - Ecotec Motor Swap - Pop Top Conversion - Camper Build & Syncro Conversion

[Ahwahnee]

Possibly to be filed under "straws, Grasping at" but...

You might put a voltmeter on the battery and see how far the voltage drops while the starter cranks. I'm thinking a drop to about 10.5V is normal. A faulty starter could draw enough current that a cold engine would not get good spark.

My clue for the above is that it sometimes fires just after you release the key. That, plus the fact that it appears to be a starting problem rather than a running problem.

Then again, could be something entirely different.

[DAV!D]

[crazyvwvanman]

Put the voltmeter on the coil, the wiring post where the multiple black wires attach. Watch the reading while the engine cranks for several seconds or longer.

Mark

[DAV!D]

[Wildthings]

The buzzing could be the FP relay opening and closing, or the FP relay doing so. The problem could be the relay itself or the ignition switch. Good chance it could be a bad ground. A jumper from the B+ terminal on the alternator to the + terminal on the coil should give you a clue as to what is happening.

[DAV!D]

Well good news is, I managed to get the van started and out of the woods. I drove it into Nederland, Co shut the van off and tried to restart it doesn't engage the starter at all.

It doesn't click like a bad solenoid just the buzzing and nothing more. I suspect that means it's likely something to do with the ignition switch.

Can anyone confirm that the ignition switch could also cause the van to get the intermittent spark while trying to start it?

When I did get it started, it was after I had been turning over the engine but the timing light showed no spark. When I let go of the key, the timing light flashed and the engine started. Once again pointing to the ignition switch or maybe the wire to the coil.

I'm wondering, if I can rig up a push button start switch as a work around until I can find a replacement ignition switch. Anyone have ideas on that?
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86 Syncro Build - Ecotec Motor Swap - Pop Top Conversion - Camper Build & Syncro Conversion

[Ahwahnee]

[DAV!D]

[Wildthings]

Check the voltage between the + side of the coil and the engine block when you are cranking the engine. If it is too low the engine may not start until you release the key. A failing coil will require a higher voltage to fire than a good coil.

[morymob]

Since it seems to be starting normally pullthe wire u found loose at starter , see if your cond returns if conn was a loose fit could count 4 intermitten start make sure its a tight fit.releasing ign key & starting, I would replace ign sw.

[DAV!D]

Ok, I didn't get to do much due to work today. However it has lost spark two times since yesterday when trying to start the engine and I've figured out something slightly strange.

Seems if I unplug the ECU and then plug it back in, I get spark to start the van on the next try. Seems anytime I lose spark, simply unplugging the ECU and plugging it back in gives it spark for at least one start attempt.

I'm not sure what to make of that, as all the pins on both the harness plug and the ECU seem fine. I don't happen to have a spare ECU lying around and I'm not real happy with the idea it might be a ECU issue.

Anyone have any ideas, before is start looking for a ECU?

Keep in mind this is a 2.1 engine and electronics in a 84 van.
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86 Syncro Build - Ecotec Motor Swap - Pop Top Conversion - Camper Build & Syncro Conversion

[Wildthings]

I would spray the contacts in the connecter with an electrical cleaner and then maybe something else designed for electrical use that would keep corrosion at bay.

[DAV!D]

[DAV!D]

Bump again for any new ideas..

The loss of spark issue is getting worse and worse. It went from randomly happening from time to time, to happening very regularly.

The problem seems to be solved temporally by unplugging the ECU and plugging it back in. However once the engine is warm, it's sometimes incredibly hard to get the van started a second time.. If will,fire and stall out soon as I put it into gear, over and over like it loses spark or something.

When I do get it started on a cold start, prior to it warming up completely, the van will often stall out and almost seems like it's losing spark at times if I'm at a red light or stopped. (Doesn't seem to do it at speed). Yet once the van is completely warmed up it runs great.

I'm trying to get my hands on a ECU from a guy that had it listed on CL but I've yet been unable to get a meet up time with him. This problem is getting worse which makes me scared what ever is causing it, will eventually fail leaving me stuck.

Is there anyone at all that has any other ideas as to what could cause this? I have to order a coil, so I can't replace that yet and I'm hoping the guy with the ECU will answer me back by this weekend.

I'm just at a loss of anything else to try at this point.


Again I want to mention, this is a 2.1 engine from my 86 with the Bosh electronics/ fuel injection.
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86 Syncro Build - Ecotec Motor Swap - Pop Top Conversion - Camper Build & Syncro Conversion

[dhaavers]

Anyone in your neighborhood that can swap in a KNOWN GOOD ECU?
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86 White Wolfsburg Westy Weekender
"The WonderVan"
<EDITED TO PROTECT INNOCENT PIXELS>

[Ahwahnee]

[DAV!D]

[geo_tonz]

Seems like you started down the ignition switch road, then backed away from it...have you eliminated that? It is a cheap replacement that takes 2 minutes to swap out and is a common point of failure, especially if you had problems before that required a lot of cranking. The switch heats up and deforms and you get various intermittant failures.

The next time it fails to start try this (quote from thatvwbusguy I just posted in another thread):

[Tom Powell]