Car Was Hot And Shut Off - Wouldn't Start...

[David T]

No one has mentioned an overheated fuel pump. That is something to check too. I think it is more likely for the fuel pump to overheat in the LA heat rather than some quirky ignition gremlins. When was the last time you replaced your fuel pump and pickup hose? Also, since you had your AC on and the fans were blowing a bunch of hot air on to the fuel tank, further leads to me think your pump might be dying.

The next time it dies either check for spark or shoot a little Ether into it to confirm lack of spark or lack of fuel. Your symptom sounds like a bad impulse coil. The ignition coils either work or don't, they don't fix themselves by cooling. The ignition ECU also works or doesn't and they don't generally fail. Changing the impulse coil is a pain because you have to take the distributor out and take it all apart.

[kings1527]

The next time it dies either check for spark or shoot a little Ether into it to confirm lack of spark or lack of fuel. Your symptom sounds like a bad impulse coil. The ignition coils either work or don't, they don't fix themselves by cooling. The ignition ECU also works or doesn't and they don't generally fail. Changing the impulse coil is a pain because you have to take the distributor out and take it all apart.

Thanks David, but with the readings I was getting on the impulse coil when I got the car to act up again, wouldn't that confirm that the impulse coil was ok? When it was hot and symptomatic, the impulse coil was reading over 700 ohms.

[kings1527]

And I seem to remember today that the tachometer was fluttering as I was trying to start it. From what I've read, that would rule out the RPM relay, impulse coil, and ignition ECU. Even more likely this could be a ignition coil problem?

[Bitsyncmaster]

I agree we need to narrow down the cause to be fuel or ignition. Also agree you should carry a can of starting fluid to help you find the cause. So when the problem happens again, quickly remove the air cleaner, give it a shot of starting fluid and see if it makes the engine "spudder". You may have to do the test a few times depending on how fast the problem cures itself. The gas in the tank will get very hot with less than an hour of driving on a 100 deg summer day.

[kings1527]

I agree we need to narrow down the cause to be fuel or ignition. Also agree you should carry a can of starting fluid to help you find the cause. So when the problem happens again, quickly remove the air cleaner, give it a shot of starting fluid and see if it makes the engine "spudder". You may have to do the test a few times depending on how fast the problem cures itself. The gas in the tank will get very hot with less than an hour of driving on a 100 deg summer day.

Sounds good. I'll try to get it to do it again.

I had someone mention to me about the yellow wire (capacitor?) coming off the terminal of the ignition coil. They referred to it as a "condenser" Dave (or anyone): any knowledge on this or the possibility that this is factoring into my problem? Over on Today, I saw a post that mentioned this wire is only related to reducing radio interference but this other guy that I talked to said the condenser was the cause of his problem.

[Kherns]

I'd rather say, this could be the problem.
Happenned to several owners here in France, and recommended by our Guru !
This saved a friend o'mine whose DeLorean was blacking out every hours or so, and
he had to let it cool down....once he unplugged this yellow litle bugger, problem disappeared.
Alex's case looks really similar to that.

[David T]

I'd rather say, this could be the problem.
Happenned to several owners here in France, and recommended by our Guru !
This saved a friend o'mine whose DeLorean was blacking out every hours or so, and
he had to let it cool down....once he unplugged this yellow litle bugger, problem disappeared.
Alex's case looks really similar to that.

If you think it is the condenser just remove it and see what happens. Doubtful it it the cause but possible. It is there to reduce interference on the radio. Taking measurements is not a good way to confirm since you have to disturb it just to check it. The Ether is a better and faster way to check. If you get no response you KNOW you have no spark.

[kings1527]

Bad ignition coil.

I replaced it the other day and all seems to be well. Before swapping in the new coil, I drove to work and it stalled out on me once but that was it. Later in the day, I installed the new coil and I couldn't get it to stall once even while under heavy load with the AC and headlights on. Stalling was becoming a common occurrence. I haven't had the chance to drive it on a real hot day and test it that way but there's already been a noticeable improvement.

So to recap:
-car would occasionally stall out while driving. Car would start right up again.
-after driving for a long time and pre-heating the engine compartment, the car would suddenly die and wouldn't start for at least an hour. Afterwards, it'd fire up and everything was fine again.
-after the car dies from the heat and I'd try to start it, the tachometer would flutter during cranking. Apparently that test rules out the impulse coil and ignition ECU.

Thanks again for the help!

[DMCMW Dave]

What kind was the one that failed?

[kings1527]

What kind was the one that failed?

It was what I presume to be original to my car Bosch OEM coil. I don't have any record of a previous owner changing it out and it definitely looked like it has been in the car for a long time.