LT1 running great, then old problems reoccurring.
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LT1 running great, then old problems reoccurring.
'94 Firebird Formula LT1. I bought it in late May, she drove beautifully for a week, then randomly she started acting up. She'd run for 10 mins and die for the day. (Wouldn't start until the next morning.) I replaced the ICM, ignition coil, and ignition switch and it was still the same. I decided to replaced the distributor, Bam! She started up and ran great for an hour before I decided to turn it off.
Less than a week later, she died going down the road. I had to sit and wait before it'll restart, which is always random. Sometimes after a 5 minute wait, sometimes an hour wait. We found out the ICM was bad. We replaced it, she died again, then found out the coil was bad. Replaced it, she died again, and found out the ICM went bad again! We decided to replace both the ICM and the coil at the same time. After that she was perfect. I could actually run WOT for a few seconds and the car wouldn't die.
Then last night, on the way back from the hospital, she died again. Same issue as before. This time, the battery ran down quick. Now, the car is left stranded in a ditch in the middle of nowhere.
I'm officially fed up with this car. I've poured every sweat drop I have into this car and still don't know what the hell it is. Should I junk the damn thing? Or does anyone out there have a clue about what the hell is wrong with it?
Less than a week later, she died going down the road. I had to sit and wait before it'll restart, which is always random. Sometimes after a 5 minute wait, sometimes an hour wait. We found out the ICM was bad. We replaced it, she died again, then found out the coil was bad. Replaced it, she died again, and found out the ICM went bad again! We decided to replace both the ICM and the coil at the same time. After that she was perfect. I could actually run WOT for a few seconds and the car wouldn't die.
Then last night, on the way back from the hospital, she died again. Same issue as before. This time, the battery ran down quick. Now, the car is left stranded in a ditch in the middle of nowhere.
I'm officially fed up with this car. I've poured every sweat drop I have into this car and still don't know what the hell it is. Should I junk the damn thing? Or does anyone out there have a clue about what the hell is wrong with it?
Last edited by Bow Tie Power; 11-10-2013 at 01:24 PM.
#2
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You haven't said anything about diagnostic steps you have taken. Are you losing spark? Have you checked for any trouble codes? How are you determining that all these things are going bad?
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Haven't checked for codes because I don't have an OBD-I tester. And she is losing spark. I'd get the ICM tested at AutoZone and they continuously test bad.
#4
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Are you using heat transfer compound when installing the ICM?
IMHO, you must have a scanning solution to work on a modern car. Everything else is just guessing.
IMHO, you must have a scanning solution to work on a modern car. Everything else is just guessing.
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Yes, I used the heatsink compound with it. I also spaced it far from the head. My friend is under the assumption that the distributor is faulty since it's a Cardone and recommends us to replace it with a better brand.
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#9
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I had a bad engine harness take out multiple fuel pumps and other ignition related components. It did mostly the same thing you described on a daily basis (run fine for about 15 minutes then become almost impossible to keep alive and have to leave it overnight) until I had someone make me a brand new one with all new connections. I am not saying to jump immediately in to replacing the harness but have someone check it out for burnt/exposed wires and poor grounds.
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I had a bad engine harness take out multiple fuel pumps and other ignition related components. It did mostly the same thing you described on a daily basis (run fine for about 15 minutes then become almost impossible to keep alive and have to leave it overnight) until I had someone make me a brand new one with all new connections. I am not saying to jump immediately in to replacing the harness but have someone check it out for burnt/exposed wires and poor grounds.
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Well, I managed to get the car started and she drove 65 miles home with no problem (yet it was also on the interstate on a cold night). The next day, she decided to not to start at all. I took the ICM to AutoZone and Advance Auto Parts and I had them test it about 10 times each and it passed every test. We put the car on an OBD-I scanner and no codes came up. Also, the CEL is not on. We also checked for fuel and it's good. To this day, she still will not start because of no spark.
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After searching through every single wire and harness on the entire wiring harness, I found a nasty break in one of the wires that goes to the coil. This was not like that before. I'm certain that's the reason why it won't start now and will be replaced first thing in the morning but since it wasn't like that before, I highly doubt that's the reason why it was dying before.
#16
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Since you've found one wire problem, double check the grounds at the coil. One is a braided copper strand that goes from the coil mounting stud to the frame rail on the driver's side of the body inboard of the driver's side fender well. The other is on the same coil mounting stud, goes into the harness.
http://shbox.com/coil/coil.html
"...Take care when removing the nut where the ground lugs are. If necessary, hold the stud still with a wrench to keep the lugs from rotating and possibly tearing loose from the wires."
http://shbox.com/coil/coil.html
"...Take care when removing the nut where the ground lugs are. If necessary, hold the stud still with a wrench to keep the lugs from rotating and possibly tearing loose from the wires."
#17
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Here's an update. I've replaced both pig tails to the coil. She started and drove fine.. for about 10 minutes and she shut off. I tried to start it and, of course, it wouldn't start. I waited for about an hour and she started up so I drove it home and parked it.
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Whenever I replaced the ignition switch, I only noticed one difference between the switch for an automatic and one for the manual: The automatic has a black plastic piece. Because of that, the automatic was about 25 bucks more. One of my friends decided to save a few bucks, I could buy the switch for the manual, take off the black plastic piece from the automatic one and install it to the manual one and it should work. It starts the car with no problem. But that couldn't prevent the car from getting spark... could it?
Last edited by Bow Tie Power; 11-06-2013 at 06:40 PM.