Ok so, Im new to the wonderful world of Camaros, and its my first day on the forums. I bought this 91 Z28 a few weeks ago and it ran fine then. By the time I went to go pick it up from the fellas house, it wouldnt start and I had to have it towed home. (he of course knows nothing)
Since its been home... the car cranks, motor turns, but fuel pump wouldnt work. Replaced relay, nope. Replaced fuel pump, nope. Buddy came over and we hard wired it from the battery to a toggle switch. Fuel pump works fine now. (turns out the old one did as well)
Im still having the same problem though, cranks but wont start. No gas smell on the spark plugs. Im pretty sure Im getting spark since I was able to get a fireball and a forced run for a second after spraying starting fluid into the throttle body.
Injectors are getting power.
I think this may be something to do with the security at this point. Since it prevented the fuel pump from working until I ran it from the battery. Also, the only dash lights coming on when I turn the key to accessories are for the air bag and 'security'.
Ive taken too much of this car apart trying to figure it out, so before I drive myself more insane, any ideas would be appreciated.
Thanks fellas, and its great to be onboard!!

 

1991 car has VATS - Vehicle Anti-Theft System. This VATS disables two things, the starter enable relay, and the injectors. So, if your starter works, usually not a VATS issue. And if injectors are firing, then definitely not a VATS issue.

The car is wired from factory for the fuel pump to prime for 2 seconds when key turned on - to send fuel to injectors (since they don't hold fuel like a carb does). Then, after car starts, the fuel pump will run always until car turned off. This happens through the fuiel pump relay you say you replaced.

So - are you sure you replaced the fuel pump relay, and not a fan relay? Fuel pump relay only one that will have a grey wire to it. And, did you check the connector to relay to make sure it wasn't shorted out?

Now, you have fuel pump wired directly to battery. Hope you used an inline fuse!

Is this a TBI car or a TPI car?

If it's a TPI car, check fuel pressure - there's a schreader valve pass side fuel rail - Autozone/Advance has a "free" rental pressure guage you can get - need like 40+ psi at fuel rail.

If it's a TBI car, no valve to check pressure - have to get an inline fuel pressure gauge and install. But you can remove the fuel line, grab a gallon jug, put line into jug, turn car on, and see if fuel is really coming out through the feed line (which is the larger of the two lines ruinning to the TBI).

If it's getting gas to the fuel rail (TPI) or to the TBI unit, then it's no longer a gas issue - that means spark or air. I'd start looking at spark - maybe the ignition module inside the distributor under the rotor button.

 

As far as the fuel pump relay, Im pretty sure its the only one that has 5 wires. Thats the one I switched out. Since each relay appears to be the same, I also switched each one with a few spares I picked up and that made no difference. Assuming the extras I had were somehow all bad, I got the new one.
I also was sure to put in an in-line fuse from the battery, so were good there.
This is a TPI, Ill check the fuel pressure how you described when I can get a chance this week...
I also forgot to mention that I did check the Ignition control module under the distributor cap yesterday. It was tested at Autozone several times and its good.

 

Can I revive an old thread, did you find out what your problem was???