ignition control module

[Fric0]

my problem is im running on two cylinders (1 and 4) which in the ignition coil those two are together, well, i swapped the coil and it still is dead in those two cylinders. So we tested wher ethe wires hook up to the back of the coil and im not getting the ground pulse for the plugs to fire the two cylinders. one of the other techs made a suggestion that it may be the ignition control module, which controls what the coils do (correct?). I went to my laser to swap the module and its got two less prongs on it due to the fact that the harness for the coil and the module on both cars are different (tach and fuel reg.). so before i go and spend 150+ on and ignition control module, what else could it be that i could throw into play here? if an ecu, then could the two ecus be different? Both 91 models (talon tsi awd and plymouth laser rs T fwd).

Anything?

EDIT: and YES the timing is correctly set.

 

[steve]

one of the other techs made a suggestion that it may be the ignition control module, which controls what the coils do (correct?). I went to my laser to swap the module and its got two less prongs on it due to the fact that the harness for the coil and the module on both cars are different (tach and fuel reg.).

Sounds like one car is a 90 and the other a 91+. Or somebody stuffed an older JDM swap into a car.

If you have a scope you can look at the output from the ECU to the power transistor module (igniter, ignition control module, etc.) to see if the ECU is generating a pulse. From there look at the output of the transistor and see if it's pulling the coil low to charge it.

ECUs commonly go bad but then also need a good timing input to do everything else so check the CAS to make sure it's outputting the TDC (2 per CAS rev) and Cam Angle (4 per CAS rev) signals. IF the ECU doesn't get the Cam Angle signal it doesn't know when to fire cyls 2 and 3.

 

[Fric0]

they are both 91's... dec/90 and may/91.. would the dsm motor and jdm motor have any difference?