I have a 1987 gta which now has a supercharged 355 30 lb injectors accel intake and msd distributor, it was running great and one day just would turn over without starting. I went through everything to find good spark good fuel pressure good ecm but no injector pulse, where do I go from here, is there a pick up coil or something telling the ecm when to fire the injectors?

 

Do a search for ICM or search injectors won't pulse. You have an MSD distributor, did you install it? If so, you should have instructions for it and how to connect to your ignition system. GL

 

No I did not install it I bought the car from a friend and it ran excellent. I parked it and the next day it just turned over and never fired up and has been that way for a year now, it doesn't have vats and there has been so much work done to it I'm having a hard time tracing wires but not to sure what to look for. It has a dfi computer in it

 

Don't know about DFI computer but, GM system uses the ICM (ignition control module) to signal that the engine is turning (cranking or running). The ICM (located in the distributor) tells the ECU when to fire the injectors. There are no crank position or cam position sensors in the GM TPI system, it uses batch fire system so no need for these sensors. Does your DFI system use a crank sensor to fire the ignition coil or does your MSD distributor control the coil firing? Can you get schematics for your computer, it would help greatly in diagnosing your problem.

 

Looking at some of the other DFI threads, I see the distributor controls timing and "probably" sends a signal to the computer. If the computer does not see this signal, it will not fire the injectors, just like the GM system. Have your ignition module tested or try replacing it, be sure to use a quality part as there are threads loaded with people buying "replacement" parts only to find it is no good. GL and let us know!

 

I'm looking at the distributor for an icm but I don't see one, the msd distributor p/n 8461 has a blue coil with a purple and green wire going directly to the msd ignition box. The factory wire which is purple and orange has been cut and the yellow wire is going to the white wire in the ignition box also. I'm not familiar with how the msd system works with the fuel injection and what to test

 

OK, my bad. The distributor tells the ignition box (6al? or whatever) when to fire and the ignition box should have a tach signal output. This output is what is fed to the computer to tell it the engine is turning. The ignition box is your ICM so to speak. I am not absolutely sure about this but from looking at some threads on other forums and looking at the Jegs site for Accel DFI this is the conclusion I came to. HTH. There should be a tach terminal on your ignition box and at the computer.


Not sure what you got with the car, but there should be tuning software for the DFI system. According to many threads, the software dashboard will indicate if the computer is seeing RPM.