thirdgennewie

I Just purchased a 91 camaro rs 305 and when I start the car it runs for a good 3 seconds and then throttle body starts spitting fuel and the car shuts off , it also makes a funney noise, if you could help thankyou i need to get back on the road.

kkingsrulee

What do you mean "Starts spitting fuel"? Are you sure the fuel pump is operating? You should be able to hear it "hum" when you put your key in the second position before you start it.

It's definitely a fuel delivery problem.

Need more input though.

thirdgennewie

yes i definetely hear a hum so i think the fuel pump is fine, but alot of fuel dumps on the top on the two butterfly valves that open when you start the car and it makes a hissing noise like air is coming out thats loud, and when i started it another time and the fuel wasnt sprayying as much and the noise was not there.

kkingsrulee

Check your vacuum lines around the TBI unit, you need to hook up a fuel pressure gauge to the fuel inlet line to the TBI unit and measure your fuel pressure.

thirdgennewie

exactlyy where do i test the fuel pressure line at? I have replaced the injectors and they spray fine now and i also replaced a heater control valve but my question is if the car is still turning on but driving like its gasping for air with a putt putt noise?? is the fuel pump still intact and can it be the fuel filter??? thanx in advance guys

1984_350_lt

check for vacume leaks,

thirdgennewie

thanks everyone I had the tank dropped and it was the fuel pump and a torn hose

thirdgennewie

i need to know where the oil pressure sending unit is on my 91 camaro if anyone has an idea it would be greatly appreciated

MightyMouse

It is just above the oil filter.

thirdgennewie

Ok here's where we are at. No fuel pump signal to the relay while starting. 10.8v between the orange and gray wires on the FP relay connector when ignition switch is in the on or off position but no start. If I jump gray wire at connector with known good 12v supply the FP runs and car starts. When I measure volts between Orange and gray wire with the car running I get 12v. Disconnected the OPSU, 3 wire, red,yellow,black, and tried to start. Nothing. Jumped and measured voltage at red and black wires at OPSU (2.4v) and nothing. Relay is good. FP fuse is good. Where should I look next? Seems like I am not getting a signal to prime the FP.

Pat Hall

iTrader: (31)

When my TBI wouldn't do the 2 second prime and wouldn't start, it ended up being the 10 gauge wire that's incorporated into the positive battery cable. It had corroded. That wire powers the whole fuel pump circuit. I crimped an eyelet on the end and hooked it back up to the positive terminal and it fixed the problem. Might not be your problem, but it's an easy thing to check.