Ajdd94

I have a 92 tbi v8 camaro that i bought about two months ago, since then ive been trying to get it to run right. i had a problem with VATS so i bought a reprogrammed chip so that is no longer a problem. My problem now is whenever i try to crank the gas gauge and oil pressure gauge wont move up and it WONT start up unless they do move up. the 2 gauges are currently stuck at halfway so the car will start up it stays on but occasionally turns off and when it does turn off on its own the gauges go back to zero and it wont start up. the only way i get it to start up is if WHILE im cranking i press the gas pedal very fast and repeatedly as that causes the gauges to move up very slowly until it starts up. my mechanic told me the injectors were barely spitting when i was doing that but it started up and stayed on and i drove it home one block away and i even put the car in 1st gear and slammed the gas to see if i would get a stall but no it stayed on. can a be a bad fuel pump? or injectors maybe fuel sending unit? all help is greatly appreciated

FormulasOnly

You're gonna have to start by checking your fuel pressure

Ajdd94

link on what to buy and also where to plug it in?

Ty92Z

iTrader: (11)

Sofakingdom recommended adding a gallon of lacquer thinner to an almost empty tank of gas to a member on here who had a car that had been sitting for years. Let it run a couple of minutes after adding the lacquer thinner to get it into all the fuel components. Shut it off and let it sit a day. Add fresh gas and it should run much better. I tried it on a car I had that sat for 10 years. I had already cleaned the tank, changed the sending unit and added a new pump as mine were completely shot of course. It ran with the new stuff, but not great because of the gummed up throttle body. Tried this trick and it ran so much better. Don't have to rebuild the throttle body now. Lacquer thinner is cheap, so it won't hurt to try it.

antares57

iTrader: (8)

The coils inside your fuel injectors can overheat and stop working. Ohm your injectors to see if the coils are okay. They should ohm about 1.2 with a voltmeter. Observe your spray pattern when it is running or trying to start, should be conical and not dripping. You can also check if your injectors are pulsing by using a 9-volt battery to the injectors. When you touch the last lead to the injector you should here a click. And, yes, as stated above, you should check your fuel pressure. You have to get a special adapter and gauge to do this. Your mechanic should have one.

Ajdd94

all useful information ill try it.. keep the ideas coming on anything else i should test

Ajdd94

Let me include that i have replaced starter, custom chip, fuel filter, and oil pressure switch which was leaking oil at the connector could the oil short something since it wet the wires?

mrestrictrplate

iTrader: (2)

hmm... never heard of the lacquer thinner trick.. I have a few cars to try that trick out on.

Ajdd94

Quick update, I haven't checked fuel pressure yet but I ran some tests.. At the fuel pump relay there is voltage at the hot wire (11.67vdc) and the fuel pump primes when I jump it to the grey wire that goes to the pump, I also applied a test light to the ecm(green/white) wire at the relay and that checked out fine as well. I ohmed the injectors and they were both 1.6 ohms.. When I turn the key to ON the fuel pump does not prime every time it does it when it wants to, BUT it does prime while cranking which I'm sure is because of my oil pressure sending unit kicking in. I have not checked the ground for the fuel pump yet because I don't know where it is, does anyone know? What other problem does this sound like ? Thanks

Ajdd94

Reviving this old thread because the problem came back... The car started driving fine after posted this. I never found the problem the car was starting and driving fine then out of no where it won't start. The fuel pump wasn't turning on when I turn the key to on and the fuel gauge was dead. so I let it sit for a week.. I come back turn the key to on and now my fuel gauge is moving and the fuel pump primes and it starts.. It's bound to go bad again so I want to kill this problem and be done.

Ajdd94

Anyone?

OrangeBird

iTrader: (1)

I'm afraid no one is gonna be able to come up with the exact right answer for you here , and here's why ;

It sounds as if you could have a connection in one of the harnesses that has what's called an "intermittent open circuit" . Obviously it appears to be in a circuit that's powering your dashboard , hence the gas and oil gauges not working when it won't run , and also of course the engine's spark or fuel systems are affected also since it won't run when this happens . The best you can do here is to take note of exactly what doesn't work , use the car's wiring diagrams to determine what feeds power to the group of things that aren't working , and then using a voltmeter begin following the circuit from where it originates (yes start at the battery terminal on the starter solenoid and work your way inward into the car's wiring) till where the circuit looses power . Now in between that big lug on the solenoid and where the power actually arrives at your fuel gauge (and ECM , and ignition coil , and so on) there are a number of things that all could become intermittent , things like ; Fusable links , wiring itself , wiring connectors , connections to fuses in the fusebox , switches (like the ignition switch may be a damned good likely candidate here too) and anything else that may be in the circuit between the battery lug and where power is lost . I mentioned connectors in the harness first because usually things like a failing ignition switch , for example , won't act up , then work perfectly for a year , then act up again , this is the usual territory of a bad connector that can be "made" or "broken" at pretty much any interval depending on how it's gone defective .

Of course , this only applies to when it's not able to run , trying to troubleshoot an intermittent is the worst because you have to wait for it to be doing the failure before tracing the circuit with the meter will find it . If you have lottery winning luck you could begin examining connections in things like the ignition switch and the dash/engine harnesses , but like I said , it's lottery winning odds as to whether the problem will be that obvious to be found with a visual inspection only .

Ajdd94

Thank you orangebird I will look into it

Ajdd94

Just a quick question .. with the fuel pump relay connected and key ON, is there suppose to be 9v on the black/white ground wire? I went from that wire to a ground on the body and received 9 volts is that normal?

GeneralDisorder

iTrader: (1)

All grounds should be at the same voltage potential if they truly are grounds. I think what you are seeing is the relay coil ground isn't connected except for about 2 seconds on key-on for the fuel pump prime. After that you are seeing 9v because you are completing the circuit through the coil and the added resistance of the coil is dropping your reading to 9v. That would be typical of fuel pump relay operation.

Rick

Ajdd94

Ok. Only problem is that my relay is not clicking and sending voltage through my GREY wire to the fuel pump. I'm getting the 2 second voltage from my ecm green/white wire, confirmed by a test light. Also the relay is good I checked it with a external power source. This has me confused since the ground and ecm wire control the coil and they both SEEM like they are ok.

Ajdd94

Update: while attempting to trace my black/white ground wire from fuel relay I was removing things to trace it and I could only get as far as behind the intake manifold. I gave up because I couldn't find anything so I plugged everything back in. I went back inside the car and turned to key on one last time and guess what.. my FUEL PUMP is priming and my gauge is now working.. I run a quick test on that ground wire that I thought was weird having voltage on it and there is NO VOLTAGE when all is good and relay is clicking. Anyway I go to crank the key and my fuel gauge dies and fuel pump is no longer priming. Where does this black/white wire from the fuel relay go. I'm starting to believe this is a faulty ECM problem.