I am going to second 1project on this. Is actually sounds like a bad pickup coil in the distributor. I had that happen on my s10. It would die, then after sitting it would usually restart. On all tbi engines my mechanic always replaces the distributor on nostarts.
Square body stepsides forever!!!
Thanks for the comments. This approach seems reasonable and since the stalling/dying is the overriding factor at this point I'll be looking into this. A couple of questions (which will demonstrate my lack of knowledge and understanding of the components involved):
1) How does one check the resistance of the pick up coil. Yes, I have a multi-meter. But what exactly is the pickup coil? I presume it's part of the ICM. Which pins do I check? I presume the resistance should be low but what value?
2) If the pickup coil is part of the ICM then the old unit had the same problem but did it much less frequently. The replacement ICM is stalling/dying every few minutes and doesn't specifically have to be "hot" as it has done it within 5 minutes of starting the engine. Do I need yet another ICM? If so, a particular brand?
I'll report more later today.
Thanks again.
The pickup coil is located at the center of the distributor. The distributor shaft passes thru the center of the coil assembly. The two leads from the coil attach (ie. plug into) the ICM. Unplug the coil to ICM and with your multi-meter you can check the coil for shorts to ground and measure the resistance of the coil which should be 500-1500 ohms. To replace the coil, you need to pull the distributor and remove the distributor shaft from the housing to access the coil. Replacing the pickup coil does not require you to purchase another ICM.
Thank you, very helpful.Originally Posted by Eds
Prior to starting the engine today I checked the resistance of the pickup coil - 1,100 ohms. Just for grins I checked each pin to ground and moved the wires, pulled and pushed gently to see if there may be some sort of intermittent but everything checked okay.
I started and stopped the engine several times and let it idle for 20 minutes or so in the garage. It did not die during that time and I did not get a check engine light signal either. There are some other odd things about the idle and I'll explain those in another post. I may have also found some other unusual aspects of my installation that will be revealing but I'm holding off on describing those until I take it for a test drive. With a little luck I'll make it around the block a few times and run a few errands.
More to come...
Speculating on why the engine was dying...
I installed the ECM under the A/C & heater duct in the passenger footwell area. It's visible and easy to access. I painted the ECM box black so it would blend in with the A/C & heater duct.
The other day when I was checking wiring and looking for reasons that the engine was dying I looked at the A/C & heater duct and noticed some moisture. When I removed the ECM to check its connections I found a small amount of moisture on the sheet metal ECM enclosure. I subsequently removed the access panel for the PROM but did not see any moisture inside the ECM enclosure. But any moisture, a drop or two of water from the A/C condensation might cause problems with the ECM.
Upon further inspection I'm not certain if the moisture is condensation from the A/C or maybe a leaking heater core.
The ECM is temporarily sitting on the floorboard in an effort to keep it away from any moisture that may be coming from the A/C & heater duct.
What are your thoughts? The engine didn't die in my recent series of test. Neither did I get a check engine light. It's too early to say it's "fixed" but maybe this moisture thing was causing some problems.
Is it reasonable to disassemble the ECM box to look for moisture/damage? Looks like a few screws hold it together. Do I run any risk of damaging components inside? If it's working now maybe I should hold off opening it. I obviously need to fix the moisture in my A/C & heater duct before I put the ECM back into position.
Last edited by nvestysly; 08-06-2018 at 12:59 AM.
This is similar to what I went through with my truck. In the barn it started fine and ran for quite a while. Days later I replaced the battery only to find that it cranked but would not start. I tried pouring some fuel into the engine but it still would not start that was at 11:00 pm so I called it quits. Four days later, with my laptop connected and time set aside to diagnose the no-start, it started fine. I let it idle for over 1/2 hour then drove it out of the barn and parked it. I shut the truck off for about 20 minutes, restarted it, and drove it to the end of the driveway to wash it. I spent over an hour cleaning the exterior then started the truck again. I washed the engine and ran the truck for another 20-25 minutes for the engine to dry. I shut the truck off while I cleaned up my supplies then it wouldn't start.Just for grins I checked each pin to ground and moved the wires, pulled and pushed gently to see if there may be some sort of intermittent but everything checked okay.
This intermittent issue was caused by a broken wire inside the pickup coil. The wire made contact temporarily. Once the wire stopped making contact I was able to confirm my suspicion. Luckily the wire stayed broken long enough to find the problem.
It's definitely a good idea to solve the moisture problem in your a/c ducts. You could visually check the ecm for problems as well. Water damage can show up as white corrosion at the solder joints or as green corrosion on various circuits. I would probably wait for a string of successes with the ecm residing in its temporary home before I decided to pull the case apart. In fact, I would probably purchase a spare ecm from a junkyard before tearing into the one currently in the car.
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