92 engine won´t start
Thread Starter
Burning Brakes
Joined: Nov 2000
Posts: 810
Likes: 3
From: Austria
92 engine won´t start
hi all
i friend of mine transplanted a ´92 LT1 in a ´80Vette, worked fine..
out of the blue, the car doesnt start anymore for unknown reasons..
he checked everything, and found out, no spark, no injector pulses, so he replaced the opti, but didnt help...
can you gigve him a direction?
thank you
i friend of mine transplanted a ´92 LT1 in a ´80Vette, worked fine..
out of the blue, the car doesnt start anymore for unknown reasons..
he checked everything, and found out, no spark, no injector pulses, so he replaced the opti, but didnt help...
can you gigve him a direction?
thank you
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
No spark AND no injector pulses sounds like no reference pulses from the distributor. Use an oscilloscope to see if you have pulses during cranking on the purple/wh wire from the distributor. If not, then open the distributor and do an ohmeter check on the pickup coil. If ok, then I would take the spark module out and have it checked at a parts store.
Also check the 2 injector fuses and the ecm/ign fuse.
Also check the 2 injector fuses and the ecm/ign fuse.
Team Owner
Joined: Aug 2000
Posts: 40,156
Likes: 45
From: San Pedro CA
I wonder what is up with the opti... a new one shoulda fixed it. The other thought is a problem with the ICM. But that would not effect the fuel delivery.
it makes me think the ECM is dying - or dead.
it makes me think the ECM is dying - or dead.
Le Mans Master
Joined: Jan 2006
Posts: 5,620
Likes: 206
From: Orlando FL
Sounds like the ECM is a likely candidate. However I would check some basic items also first.
* Turn key on and check to see if there is 12 volts on pins A and D of the ICM connector with the connector pulled off.
* Check also to see if there is 5 volts DC at pin C of the opti connector (you can remove the connector, might be a red wire).
* Check to see if any of the plug connections on the ECM are not seated correctly.
* Check other connections like grounds and any other connections and wiring modifications made during the custom install of the motor.
*The ignition switch and any related fuses.
Something wrong might give you a new direction.
* Turn key on and check to see if there is 12 volts on pins A and D of the ICM connector with the connector pulled off.
* Check also to see if there is 5 volts DC at pin C of the opti connector (you can remove the connector, might be a red wire).
* Check to see if any of the plug connections on the ECM are not seated correctly.
* Check other connections like grounds and any other connections and wiring modifications made during the custom install of the motor.
*The ignition switch and any related fuses.
Something wrong might give you a new direction.
