Z28pete, I don't have TPI, I have TBI.
It is the glorified carburetor. I have a fuel pressure test kit here now, so I am going to test that. I don't have the noid light. Some idiot was helping me at the parts store and said they didn't sell them. Guarantee he didn't know what it was, cuz every parts store should carry them. I will get one tonight or tomorrow after I test pressure.

I wrote the wrong thing in my original post. Sorry guys.

 

Okay, I am sorry, im my original post I said TPI, It is actually TBI. I do apologize and realize that makes a huge difference. Just missed it when posting.
I did do a fuel pressure test and am getting 10 psi when the pump is running and while I am cranking the engine. If i turn the key just to the on position without cranking it goes up to 10psi, then when the relay shuts the pump off it drops back down to 0psi. When cranking it stays at 10psi.

Now crazy enough... while I was doing this test, the injectors injected fuel! So now it will inject a small amount of fuel, not consistently unless I turn the key back on and off a few times...

Any Ideas?

 

I used to have a 91 RS a few years ago, it's not teal is it? A fuel delivery issue I had was with the short rubber fuel pump connector in the tank being deteriorated. Fuel pressure wants to be between 9 and 13 psi, so you're right in there. I can't say if it's supposed to hold with the key off, but with what you're reading (key on and while cranking) the engine should start based on pressure. Have you tried, just like with a carb, pouring a little gas down the TBI to see if you get ignition? At least you can then rule out spark or fuel.

 

No its not teal, its black. When I replaced the fuel pump I also replaced that black rubber tube. So I'm sure its not that. The old one was however deteriorated. I did not try putting gas directly in the throttle body. I can try that then it would rule out other issues. I did pull a spark plug and am getting spark. The plug was kinda dark. Does that mean it was running rich?

 

Okay. I tried that and it worked, started up and actually was idleing some. The injectors were pulsing, and it was running by itself. So then i pressed the gas, and it was like it was gasping for air... So maybe a vacuume leak? It did idle for a little while, but I think it flooded, because after playing with if for a little bit it wouldn't start up again. Ill let it sit for a while and then maybe try it again.

 

I am not sure about TBI, and this probably won't help, but in some applications GM used two current paths to run the fuel pump, one through the fuel pump relay and the other through contacts in the oil pressure sender. The fuel pump relay was used to prime the system and the path through the oil pressure sender took over after the oil pressure reached 5 PSI. The pump relay was set to drop off if the engine did not start within 5 seconds of cranking.

 

Pete, from what I understand, the fuel pump relay trips back on once it receives a signal that the engine is running. The circuit through the oil pressure switch is a fail-safe, to keep the pump running in case the relay fails while you're driving. More or less, the pump is wired redundantly.

 

OK! That makes sense. Thanks.

 

So, its not the oil pressure sensor. Is it an O2 sensor? It seems like it was running rich. Would a bad o2 sensor cause that?

 

SO, this turned out to be a VATS problem. Installed a resistor under the dash and it works just fine!