I have a 1991 firebird with a 305TPI that ran very strong and smooth untill one day it just wouldnt start. I left it for 4 hours and it fired right up with no hesitation at all, as soon as I turned it off it wouldnt start again. It would just keep cranking. I got it to run one last time about 2 weeks ago to bring it to may dads to work on it. It has spark, 44 PSI crank fuel pressure But injectors will not fire, they are not grounding out. I took it to the garage and they checked the VATS system which is working fine. Anybody had this problem with there car?????
I also did put a new ECM in before I took it the the garage.

Thanks

 

Double and triple check all of your connections. Make sure nothing is loose. Make sure all of the connections to the ECM are solid too. Also check the resistance across each injector. Are you getting a signal to the injectors when you are trying to crank?

 

I always pull the ign module and take it to autozone and have them test it

 

It only starts when cold...or not starting at all now?

 

not starting at all.

 

Then do a little "shadetree" experiment.

Pul the number one plug wire (easiest to get to) and holld it near the block while you have someone cranking it over...

Got spark?

If so...

put a rag around the shrader valve (or...since you mentioned you had 44 PSI FP...put you gauge back on) and see if fuel is in the line.

Next if all checks out (you have spark and fuel)...and assuming your exhasut is not plugged up (no exhaust = no air intake) then check for volatge on the injectors...got vlotage?

If not, check the INJ1 and INJ2 fuses in your fuse box.

If you have volatge,..then you must have a DMM/DVM...so monitor the other side of the injector wire, and while cranking, it should pusle to "zero" volts.

It'll take you and a helper to run the key, unless you got real longs arms (and three of them), which if that's the case I should be seeing you Sunday night when the Lakers beat the Celtics in BeanTown

 

to check ecm wiring and injectors,pull the plug from the ignition module on the distributor with i think 5 wires,not the one with 2 that goes to the coil. find the purple wire in the 5 wire plug,put a test light with the aligator clip on the positive terminal,and touch the other end of the test light to the purple wire with the key on,this will fire the injectors.

 

i had a similar problem, turned out it was the resistor in the key, for the vats system, would only read about 1 out of every 5 times, so i replaced the ignition cylinder, and the key. Works great now, all you have to do is take the key to the dealer and get the dealer key code number, then get them to replace the key