computer/ecu no good? 502 mag. help please!!
 

ive got a 502 magnum cylinders 1,7,4,6 are all out, i traced it back to the injectors, i hooked a noam light up to see if they are getting power to them and there not.

injector not firing
 

use a digital volt meter and check to see if you are getting 12V at the red wire at the injector connection with the key on.

If you are then this would tell you that the ECU injector driver circuit is not being grounded by the ECU. If you are not then you are not supplying 12V to the injectors in that bank thus the ECU can not ground what is not there.

next

If you have an early version ECU MEFI1
J2-5 Fuel Injector Driver A (2,3,5,8) - Blue wire
J2-21 Injector Driver B (1,4,6,7) - Green

Check continuity between J2-21 Injector Driver(ground) "B" (1,4,6,7) to the other wire (green) in the injector plug at either 1,4,6,or 7. If continuity is broken chances are you have a harness problem and not an ECU problem. If continuity exists then you likely have a shorted injector driver in the ECU requiring replacement.

I you have a MEFI3
repeat the steps as outlined for MEFI1 except the the following.
J1-1 Fuel Injector Driver A (2,3,5,8) - Blue wire
J1-17 Injector Driver B (1,4,6,7) - Green