Wiring harness or computer is bad?
08-02-2005, 02:18 PM
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Car: 1986 Pontiac Trans Am
Engine: 350
Transmission: 700r4
Axle/Gears: 373, i think
Wiring harness or computer is bad?
My BF and I have been trying to figure out what is wrong with my car. when i first got the car, it would cut off here and there when i was driving it, but you were able to start it back up and drive again. By the way it is an '86 Trans Am- TPI.
finally i decided to rebuild the distributor, change the wires and plugs, thinking it was an ignition issue. i used MSD products also. so last weekend we were on our way to the track and my car cuts off at a light and does not start up.
we thought it was the starter, batttery or alternator but it turns over fine. after doing all of that we came to the conclusion that the spark is getting shorted out somewhere but couldnt figure out where. so finally we figured it was the wiring harness to the computer. the other day we were checking with a voltmeter the harness itself and it was getting to be a perplexing situation. i am wondering if i should get a new harness or if the prolem if simple.
has anybody had any of these issues before and if so please offer some ideas.
finally i decided to rebuild the distributor, change the wires and plugs, thinking it was an ignition issue. i used MSD products also. so last weekend we were on our way to the track and my car cuts off at a light and does not start up.
we thought it was the starter, batttery or alternator but it turns over fine. after doing all of that we came to the conclusion that the spark is getting shorted out somewhere but couldnt figure out where. so finally we figured it was the wiring harness to the computer. the other day we were checking with a voltmeter the harness itself and it was getting to be a perplexing situation. i am wondering if i should get a new harness or if the prolem if simple.
has anybody had any of these issues before and if so please offer some ideas.
08-02-2005, 03:04 PM
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Car: 2003 Hyundai Tiburon GT
Engine: 2.7L V6
Transmission: 6-speed
Axle/Gears: 4.41
When you rebuilt the distributor, did you have the ignition control module (the black thing bolted to the lower plate) tested? My guess is that either that or the ignition coil is bad.
Did you save the old plugs? If so, what color are they? The color of the plugs can tell you a lot about what is going on inside the engine.
Keep this saying in mind: "No spark, no squirt", referring to the fuel injection. The ICM is what actually tells the ECM that the engine is being cranked or that the cranshaft is turning. If the ECM doens't see any crank (actually more like camshaft) rotation, it won't fire the injectors or spark plugs.
If the ICM needs to be replaced, it is best to replace it with an AC/Delco unit, even if the el-cheapos have a lifetime warranty. Who wants to go ahead and replace el-cheapo parts every couple years when good quality parts that are more expensive will last longer?
Did you save the old plugs? If so, what color are they? The color of the plugs can tell you a lot about what is going on inside the engine.
Keep this saying in mind: "No spark, no squirt", referring to the fuel injection. The ICM is what actually tells the ECM that the engine is being cranked or that the cranshaft is turning. If the ECM doens't see any crank (actually more like camshaft) rotation, it won't fire the injectors or spark plugs.
If the ICM needs to be replaced, it is best to replace it with an AC/Delco unit, even if the el-cheapos have a lifetime warranty. Who wants to go ahead and replace el-cheapo parts every couple years when good quality parts that are more expensive will last longer?
08-03-2005, 11:09 AM
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Car: 2003 Hyundai Tiburon GT
Engine: 2.7L V6
Transmission: 6-speed
Axle/Gears: 4.41
Did you check to see if you actually have a healthy spark, when the car cut out? Will the car start and run now, or is it still dead? It almost sounds like a blown fuse, loose connector, or something along those lines.
Did you also replace the pickup coil with MSD parts, or is that still GM?
Did you also replace the pickup coil with MSD parts, or is that still GM?
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