Continued no Start problem
06-13-2009, 11:47 AM
#1
Continued no Start problem
Hi all
Well had to step away from the car I will bring you up to date now
Thanks Mike c ChrisWhewell and theadmiral94 I corrected the wiring on the pug for the temp sensor going to the water pump.
I check for voltage at the A and D pins on the plug to the ICM I read very low voltage I took it to advanced auto but they couldnt test it i brought a new one and installed it car still wouldnt start. They let me return it. I also purchased a new coil but that didnt work as well.
Should I now start thinking about replacing the Optispark unit? I know the best is MSD but dont have that kind of money right now because I just put 3k into the before this happened.
Distributor Advanced about $200.00 witn out rotor Ebay $150.00 to $200.00 with rotor any other suggestions
Well had to step away from the car I will bring you up to date now
Thanks Mike c ChrisWhewell and theadmiral94 I corrected the wiring on the pug for the temp sensor going to the water pump.
I check for voltage at the A and D pins on the plug to the ICM I read very low voltage I took it to advanced auto but they couldnt test it i brought a new one and installed it car still wouldnt start. They let me return it. I also purchased a new coil but that didnt work as well.
Should I now start thinking about replacing the Optispark unit? I know the best is MSD but dont have that kind of money right now because I just put 3k into the before this happened.
Distributor Advanced about $200.00 witn out rotor Ebay $150.00 to $200.00 with rotor any other suggestions
06-13-2009, 06:31 PM
#2
Melting Slicks
I found the following Opti test procedure in my C4 files. I have never verified these test methods, so buyer beware.
OPTI and Spark Test
The opti has two functions in the spark process. The first thing that happens is as the cam turns, the optical section of the optispark picks up the signals by the rotation of the shutter wheel. The pulses are sent to the PCM via the optispark electrical harness. The PCM processes the signals along with other sensor input and determines the proper time for the coil to fire. The PCM sends a signal to the Ignition Control Module (ICM) and it, in turn, causes the coil to fire. The spark from the coil travels through the coil wire back to the secondary ignition section of the optispark (cap and rotor), to be distributed to the proper cylinder.
If the opti is never sending the signal to the PCM, the PCM will never send a signal to fire the coil.
Here is some testing you can do. Refer to this diagram:
Disconnect the ICM connector. Leave coil connected.
Turn key to ON.
Check for dc voltage with a digital meter at harness terminal "A" to ground and and also "D" to ground. Note: Use a high impedance meter (at least 10 megohm) when dealing with the PCM.
Result should be 10v dc or more on both terminals. If you get no voltage, use the diagram and chase back toward the coil and the ignition fuse. Power for the ICM comes from the ignition fuse and through the coil, so any of that could be bad.
If you have good voltage, switch the meter to ac scale and connect test leads to terminal "B" and to ground. Observe meter while cranking the engine. You should see between 1 and 4 volts ac (those are the pulses that trigger the coil to fire).
If you don't see the proper ac voltage the problem could be the optispark, the harness to the optispark, the PCM or any of the wiring in between. Visually inspect all the connections you can get to for poor contact or corrosion.
edited 5/16/2004
OPTI and Spark Test
The opti has two functions in the spark process. The first thing that happens is as the cam turns, the optical section of the optispark picks up the signals by the rotation of the shutter wheel. The pulses are sent to the PCM via the optispark electrical harness. The PCM processes the signals along with other sensor input and determines the proper time for the coil to fire. The PCM sends a signal to the Ignition Control Module (ICM) and it, in turn, causes the coil to fire. The spark from the coil travels through the coil wire back to the secondary ignition section of the optispark (cap and rotor), to be distributed to the proper cylinder.
If the opti is never sending the signal to the PCM, the PCM will never send a signal to fire the coil.
Here is some testing you can do. Refer to this diagram:
Disconnect the ICM connector. Leave coil connected.
Turn key to ON.
Check for dc voltage with a digital meter at harness terminal "A" to ground and and also "D" to ground. Note: Use a high impedance meter (at least 10 megohm) when dealing with the PCM.
Result should be 10v dc or more on both terminals. If you get no voltage, use the diagram and chase back toward the coil and the ignition fuse. Power for the ICM comes from the ignition fuse and through the coil, so any of that could be bad.
If you have good voltage, switch the meter to ac scale and connect test leads to terminal "B" and to ground. Observe meter while cranking the engine. You should see between 1 and 4 volts ac (those are the pulses that trigger the coil to fire).
If you don't see the proper ac voltage the problem could be the optispark, the harness to the optispark, the PCM or any of the wiring in between. Visually inspect all the connections you can get to for poor contact or corrosion.
edited 5/16/2004
Last edited by MikeC4; 06-13-2009 at 06:43 PM.