besides the VATS, what sensors/signals tell the computer that it is ok to pulse the injectors? i have a 91 305 TBI automatic. thank you!

 

IIRC, that's it. There is an oil pressure switch above the oil filter that won't allow the pump to prime if it doesn't register presure, but I think that the only thing that will prevent injector pulse is VATS.

You do have 2 injector fuses in the fuse box.

Might want to test at the ECM to make sure the injector drivers are firing, that will rule out an issue with wiring.

Oh, almost forgot. If the impedance is to low on an injector, the injector driver will not operate. Test the injector coils to see what the resistance is.

 

Sounds like that isn't doing something it's supposed to. Care to trouble shoot?

 

thanks for the great ideas. heres some more details. my car is a real pain to start in hot *weather*. strangly, it starts fine if its "hot" (i.e. been running). i narrowed it down to its not getting fuel. i then figured out its not the fuel system cause i finally got a noid light hooked up to it while it wasnt working and the light wasnt flashing. so i believe my ECM or some sensor is over heating in the hot weather cause i reached under there and the ECM was HOTTT.

 

isnt there a distributor reference signal or something? could that module be overheating? im thinkin its the ecm but i just wanna consider all possibilities.

 

Check to see if you get spark when you are not getting a flash from the noid light. The module inside the distributor may be causing the problem. Also check to make sure none of the injector windings are shorting out when they get warm.

 

Yes, you need to have power from the INJ1 and INJ2 fuses, a distributor reference signal, power to the ECM, and a valid VATS input.

If you are getting spark to the plugs, the distributor is at least generating a signal. You need to make sure that signal is getting to the ECM.