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Engine quits abruptly - won't start by Ray_and_kevin
Started on: 02-24-2014 10:21 PM
Replies: 9 (140 views)
Last post by: Ray_and_kevin on 03-09-2014 08:46 AM
Ray_and_kevin
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Report this Post02-24-2014 10:21 PM Click Here to See the Profile for Ray_and_kevinSend a Private Message to Ray_and_kevinEdit/Delete MessageReply w/QuoteDirect Link to This Post
So, we drove the new 88 GT back from Ohio on Friday/Saturday for 13 hours and 824 miles. Drove great the whole time. We stopped at 6:30AM just inside the Texas state line since both Brian and I were too sleepy to keep going.

We started the car again about 7:30 AM and heard a pop/bump/weird noise from the engine compartment. The engine stalled for way less than a second and the check engine light came on and right back off. Thought "this is a bad sign" but kept going. Made it about 25 miles down the road and the engine just stopped dead. Coasted for about a mile and stopped for about 10 minutes. Tried the engine and it started. Drove another 3 to 5 miles and it happened again. This time I left it in gear and it started back up for about a mile and then died again. Fortunately, right by an exit ramp. Got it going one last time and got it about 1/2 mile down the service road to the Exxon station where it refused to start again.

Got it on a trailer and home after 8 hours. Tried to start it and it started right up. backed it off the trailer and let it sit overnight. Started it up again to go to the grocery store and made it 6 blocks from home. Fortunately, it is down hill back to home.

So, does this sound like a collapsed muffler or collapsed catalytic converter? If so, any suggestions short of disconnecting at the Y pipe to see if the exhaust is plugged? I checked the pump and it runs and gives pressure. I didn't use a gauge, but fuel squirts out the Schrader valve. Replaced the fuel filter for good measure and still won't start.

I guess it could be the ECM, but electronics usually don't fail like that. They either work or are broken. Haven't checked the injectors to see if they are activating. I guess it could be those.

Suggestions and speculations appreciated.
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84fiero123
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Report this Post02-24-2014 10:36 PM Click Here to See the Profile for 84fiero123Click Here to Email 84fiero123Send a Private Message to 84fiero123Edit/Delete MessageReply w/QuoteDirect Link to This Post
Clogged/collapsed catalytic converters will glow red hot when they are that way, if you can get it running again, let it run while watching the converter, if it turns color, that's you problem.

Steve

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and one big pain in the ass when it doesn't



Detroit iron rules all the rest are just toys.

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mitchjl22
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Report this Post02-25-2014 02:09 AM Click Here to See the Profile for mitchjl22Click Here to Email mitchjl22Send a Private Message to mitchjl22Edit/Delete MessageReply w/QuoteDirect Link to This Post
Its worth it to take your distributor cap off and take out your ICM. It unscrews with 2 Phillips screws. Unplug it, and take it to an Oreilly (The only one that I know can test them). Have it tested, if its fine, buy some dielectric grease thermal compound, and re install. Be careful when re-installing not to pinch the wires from the pickup coil inside the dist cap.

-Mitch

Edit to fix my mistake

[This message has been edited by mitchjl22 (edited 02-25-2014).]

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Patrick
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Report this Post02-25-2014 02:20 AM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post

I'll guess it's the ICM.

Before they get completely fried, they'll often work for awhile once they've cooled down before they fail again when hot.

 
quote
Originally posted by mitchjl22:

...buy some dielectric grease, and re install.


Please please please do NOT use dielectric grease between the base of the distributor and the ICM. Use the proper stuff, which is thermal compound.
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mitchjl22
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Report this Post02-25-2014 03:26 AM Click Here to See the Profile for mitchjl22Click Here to Email mitchjl22Send a Private Message to mitchjl22Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:


I'll guess it's the ICM.

Before they get completely fried, they'll often work for awhile once they've cooled down before they fail again when hot.

Please please please do NOT use dielectric grease between the base of the distributor and the ICM. Use the proper stuff, which is thermal compound.


Correct, I got my wires crossed. Your local Radio Shack should have thermal paste. Dielectric grease is used to keep moisture out of auto bulb sockets and spark plug boots and not designed for thermal conductivity.

[This message has been edited by mitchjl22 (edited 02-25-2014).]

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Bloozberry
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Report this Post02-25-2014 07:21 AM Click Here to See the Profile for BloozberrySend a Private Message to BloozberryEdit/Delete MessageReply w/QuoteDirect Link to This Post
I agree... those are the classic symptoms of your ICM failing.
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84fiero123
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Report this Post02-25-2014 01:02 PM Click Here to See the Profile for 84fiero123Click Here to Email 84fiero123Send a Private Message to 84fiero123Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by mitchjl22:

Its worth it to take your distributor cap off and take out your ICM. It unscrews with 2 Phillips screws. Unplug it, and take it to an Oreilly (The only one that I know can test them). Have it tested, if its fine, buy some dielectric grease, and re install. Be careful when re-installing not to pinch the wires from the pickup coil inside the dist cap.

-Mitch


When you have the cap off and are looking under the top of the distributer check the insulation on the pickup coil, make sure the insulation is intact. mine started to corrode and affected drivability. while not the same symptoms it can cause problems when ever the humidity is high.

Steve
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Ray_and_kevin
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Report this Post02-28-2014 09:26 PM Click Here to See the Profile for Ray_and_kevinSend a Private Message to Ray_and_kevinEdit/Delete MessageReply w/QuoteDirect Link to This Post
Many thanks for the pointers on the ICM. I got a box of "spare parts" left over after the engine conversion. Guess what shows up at least 3 times???

You are correct. ICM's!

Not sure how expensive, but might be a really quick test if not too pricey.

Off to Autozone first thing tomorrow morning.
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Ray_and_kevin
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Report this Post02-28-2014 09:28 PM Click Here to See the Profile for Ray_and_kevinSend a Private Message to Ray_and_kevinEdit/Delete MessageReply w/QuoteDirect Link to This Post

Ray_and_kevin

181 posts
Member since Sep 2012
Forgot to mention If you are in the Austin area and need thermal grease, I have at least a 500 year supply from when I used to fix medical equipment.
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Ray_and_kevin
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Report this Post03-09-2014 08:46 AM Click Here to See the Profile for Ray_and_kevinSend a Private Message to Ray_and_kevinEdit/Delete MessageReply w/QuoteDirect Link to This Post
Well, I didn't get to Autozone until yesterday. They can't test the ICM, so I just bought one figuring it is cheap enough. Went to change it out and discovered that the brand new looking distributor cap was actually fairly old. So was the rotor, of course. The cap had all of those little metal whiskers growing from the electrodes. The spring loaded pin was also hinky. I made sure the spring was working and put the cap back on. It started right up.

I had tested for spark coming from the coil wire when it was not starting. Obviously, you can see spark from the wire ,but because it is jumping two gaps, it is not enough to light off the cylinder mixture. Another lesson learned.

So, I discovered that an old distributor spring can cause the same type of issues that a failing ICM can cause. I remember now that my 86 would do similar things just before the ICM would die. I also learned way back when that the ICM does not like high RF fields that come from things like my amateur radio transmitter.

Installed the new cap and rotor and she is back on the road!!
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