Ok so my 91 Camaro RS 5.0 will turn over but not start. I cant get the injectors to spray for the life of me. I have tried EVERTHING! Im getting voltage to the injectors but it doesnt seem like im getting a ground on the ground side. I have replaced the fuel filter, fuel sending unit, Fuel pump, ecm, I have bypassed the VATS system by connecting both big wires that go to the relay to make it crank. I have continuity between the injectors and the ECM. The ECM gets power. I have good fuel pressure and i have teared down, cleaned, and rebuilt the entire TBI unit. I am all out of ideas!!! Please help!

 

If I'm looking at the wiring shematics correctly then the computer runs thr grounds of the injectors to make them work. If you jumpered the starter relay to get it to crank the the VATS is still telling the computer not to add fuel. The VATS itself is a module and not a relay. I think you should look into a VATS problem not a injector problem.

 

I agree

 

Hi camaronewbie,
You answered a post of mine earlier "Man it almost starts" Thanks.
It seems like we are having the same problem.
I am getting ready to test my injectors for voltage etc. but am trying to make sure that I have tried every other reasonable test first.
I am going to test the TPI next for proper voltage.
I hope you don't mind my replying to you with a "ME TOO" post - maybe we can help each other somehow?
Did you remove the top plenum to test your injector voltages it looks hard to do otherwise.
I think I can do a preliminary test at the ECM.
Any thoughts would be appreciated.
Thanks, Bryan.

 

What would be the best way to go at the VATS in this case? Same is happening to me today. A few months a go I had to place a resistor in line because there was a fault reading the key.

 

Many cases putting the resistor in line is all you need to do because the wires in the column wear through. I'd double check your resistor for the correct resistance for your specific VATS module, look for a busted wire, etc. The next step if your VATS module is failing is to get a bypass module. I found one at TPIparts.net. I will note that I've never put one of these in but I'm guessing your dash will have to be pulled apart a bit to get to the VATS module. http://tpiparts.net/inc/sdetail/5186

If you had a TPI instead of a TBI then you could also have a PROM burned for the computer to eliminate its need for a signal from the VATS module.

 

My starting issue turned out to be a defective ICM. Do not buy a jegs ICM this is the second that crapped out on me. The first lasted 2 days with failure when hot. The second lasted 1 week and just flat out died with no warning. Put the stock one in and presto, works great again.

 

I hope you coated the bottom of the module with the included dielectric grease to assist in heat transfer of the module to avoid heat related failure. A better option is to get a little tube of heat sink compound from Radio Shack and smear it all over the bottom. Does a better job IMO

 

I used the tube of heat sink in both cases. The grease that was provided was dried up and there was not much.