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I have a 1992 Chevy Corvette LT1 motor this vehicle seems to shut down after warm up. I have replace the following. MAP sensor, MAF sensor, idle control valve, idle sensor, EGR valve and solenoid, purge solenoid and lines, spark plugs spark plug wires, optispark ignition control module. I just ordered a coil pack I hope this is the solution. I also check for ohms across my fuel injectors. I also replace the fuel pump I hope the coil pack is the problem scratching my head..馃槼馃槼馃槼馃嚭馃嚫馃嚭馃嚫馃嚭馃嚫
 

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Welcome to the forum.

Have you checked for codes? None of the icm & opti related codes lights the cel. Did you put heat sink compound on back of icm & it's heat sink? This is vital if you don't want icm to burn out quickly.

You need to get an oscilloscope to be able to 100% diagnose the opti low & high resolution pulses. They both should be well defined square waves with no drop out or changes in waveform. You can by a PC based scope for around $70. Get it at ebay, amazon, etc.
 

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Discussion Starter #3
Welcome to the forum.

Have you checked for codes? None of the icm & opti related codes lights the cel. Did you put heat sink compound on back of icm & it's heat sink? This is vital if you don't want icm to burn out quickly.

You need to get an oscilloscope to be able to 100% diagnose the opti low & high resolution pulses. They both should be well defined square waves with no drop out or changes in waveform. You can by a PC based scope for around $70. Get it at ebay, amazon, etc.
Here is the situation with this car this vehicle is a 1986 Chevy Corvette with an upgrade to a 1992 LT1 motor. The OBD1 port is connected to my scanner it reads no current I'm wondering if this OBD1 is hooked up the check engine light does not illuminate on Startup. What fuse is related to the OBD1 port. This vehicle was shutting down before all of the maintenance including the optispark馃馃馃...
 

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Welcome to the forum.

Have you checked for codes? None of the icm & opti related codes lights the cel. Did you put heat sink compound on back of icm & it's heat sink? This is vital if you don't want icm to burn out quickly.

You need to get an oscilloscope to be able to 100% diagnose the opti low & high resolution pulses. They both should be well defined square waves with no drop out or changes in waveform. You can by a PC based scope for around $70. Get it at ebay, amazon, etc.
P.S. I forgot to mention I had a mechanic install the ignition control module he use some type of clear silicone the part came with the heat sink compound but he didn't use what came in the Box maybe he had his own compound once I receive my coil pack I will disassemble and check馃馃馃
 

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Since your 86 corvette was changed from the L98 TPI setup to a 92 LT1, I can't help too much as I don't have access to the 86 & 92 corvette wiring diagrams. The corvette system has differences from the F-body diagrams I am used to.

One thing I have read about the 4th gen corvettes is you can read codes without a scanner. I don't know how it's done. If you have both the 86 & 92 corvette wiring diagrams, I might be able to make sense out of where your problems are.

Though, car running when cold & dying when hot is usually an opti or ICM problem, it can be other components also. For example; if your fuel pump is old & tired out, it can fail when it gets hot. Old wiring and connectors can have conducting problems that show themselves when wires heat up from the increased resistance of the wires and/or connectors

Computer controlled devices and sensors, as well as the computer itself, are all very sensitive to lower voltages caused by corroded wires & connector pins.
 

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Since your 86 corvette was changed from the L98 TPI setup to a 92 LT1, I can't help too much as I don't have access to the 86 & 92 corvette wiring diagrams. The corvette system has differences from the F-body diagrams I am used to.

One thing I have read about the 4th gen corvettes is you can read codes without a scanner. I don't know how it's done. If you have both the 86 & 92 corvette wiring diagrams, I might be able to make sense out of where your problems are.

Though, car running when cold & dying when hot is usually an opti or ICM problem, it can be other components also. For example; if your fuel pump is old & tired out, it can fail when it gets hot. Old wiring and connectors can have conducting problems that show themselves when wires heat up from the increased resistance of the wires and/or connectors

Computer controlled devices and sensors, as well as the computer itself, are all very sensitive to lower voltages caused by corroded wires & connector pins.
Check your injector, sometimes when they get hot they stop working. check the resistance cold then hot.
 

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Discussion Starter #7
Check your injector, sometimes when they get hot they stop working. check the resistance cold then hot.
I checked my coils on my injectors the ohms reading's are 12.5 across the board cold engine and hot engine. I was told to replace my ignition control module I had a mechanic change it out my coil pack seems to be very loose it needs to be replaced馃馃馃
 
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