gimpsy

I just went through a substantial tune up on the car that ended with a ground problem fixing the miss issue, as part of that quest I replaced the ICM, opti, spark plugs, wires,O2 and the EGR valve. The car was running great so I decided to do the exhaust, parked for 3 weeks swapped the exhaust and the brakes finished that yesterday and took it for a drive. I got about 10 min into a drive to brake in the brakes speeding up slowing down and such and it just up and dies, I try to restart and it kinda trys but then diesels a little then dies again. I wait a few try again and it starts and in is running fine, so turn around start heading back and it dies again. I notice the temp is up around 227deg so I let her cool off for 10 to 15 min then off I go all the way home into the garage babying it the whole way. I get in the garage and start watching the temp rise until 230 and she dies again. I have read that this is the sign of an ICM failure gets hot dies cools off runs again, so since I just replaced I get another one swap it today and same results. I am using an AC Delco ICM.

When it dies it just shuts off no matter where it is in the RPM band if you try to restart it is hard to start and then diesels until it dies, then let it cool even a few degrees and it will start fine till 230 then dies. I am stuck and looking for suggestions I am pretty sure this has nothing to do with my other problems nor the exhaust but any input would help.

Could it be vapor locking? I would think that 230 is a little hot but not that much.

Art

antfarmer2

Could be might look at the coil

MaxDaemon

Maybe kinda off the wall, but don't the fans kick in at 230? Any chance that's either shorting something, or the amp draw is sucking too much out of the system?

gimpsy

I forgot to mention that I replaced the coil with an MSD when I worked on it.
I was watching the dash when it died and I didn't see anything weird with the voltage Not sure how to check that maybe unplug the fans and watch it get hot and see what happens.

It was running fine for couple of hundred miles and I know it has gotten this hot since all the work I drove it over 100 freeway miles to the dealer who fixed my ground problem I doubt it would make it back there now.

Art

gimpsy

What if I take the coil and the ICM of the head and let it hang there so it won't get hot do they need to be grounded I could just put a jumper in. If they stay cool and it doesn't die that would tell me something.

Art

antfarmer2

Are you suppost to put some sort of heat grease between them

gimpsy

I did install the heat grease between them it came with the first one I installed.

Art

antfarmer2

Have you changed your fuel filter?

gimpsy

I haven't changed the fuel filter but I have one setting on the bench. I wouldn't think fuel because when I was trouble shooting the last problem I checked fuel pressure and it was great, also when getting the car hot there is no missing or anything runs great right up until it doesn't.

One thing I came up with that I am going to check out tomorrow is I will get it hot till it dies then swipe the hot ICM for a nice cool one not attached to the block and see if it will run or die. That should at least tell me something. I also will have more time tomorrow to concentrate on it.

Art

desertmike1

If you have an air compressor, blow air across the ICM or coil and see if that makes a difference.

Klondike

This sounds too coincidental. Like when the fans kick on it's sucking down the power and the alt. just can't supply enough to keep everything going. I'd check the condition of all the cables at the battery posts & grounds and do a load check on the battery to make sure it doesn't have a weak cell.
I had a similar problem and although the battery cable connections looked good from the outside, when I took them off, the posts had a black glass-like coating on them. Cleaned the posts & cables with a battery post brush and everything came back to normal.

gimpsy

Went out today to work this out and it wouldn't start at all. So I checked for spark and no spark (getting somewhere) swapped ICM's again, no spark. I had swapped the coil for an MSD when I worked on it before so I ran to the auto parts store and bought the cheapest one they had and tested it, runs fine now doesn't die or anything. So I called summit and they are sending me a free replacement, I am just glad this happened close to home. I think I will keep the cheap one and drop it in the storage compartment just in case. Thanks for all the replies.

Art

antfarmer2

good deal

Whiteonrice

I love happy endings! I was reading this post and hoped you would get it resolved. My kind of soap opera.