OK...I bought this bird that has been sitting for about 3 years...it turns over fine and if i pour a little fuel into the carb (tpi?) it will fire up for a few seconds then ultimatley dies...so i know i have spark....everyone was suggesting draining the fuel and getting some fresh in their, but whats the easiest way to go about that?



92 Firebird 305

 

Depends on exactly what is wrong with the fuel system - if it's the pump you will have to drop the tank etc. If it's the filter is plugged, replace the filter but the right way is to drop the tank, check it for rust - replace the pump & stuff while your in there and then replace the filter and clean the lines out. If you only do part of the job you may have it die later with another issue.

mine sat for 2 years and the tank was full of rust, the gas had condensed to a thick yellow turpintine like consistency etc. I replace and cleaned everything and it fired right up and ran very well after that. Some additive and oil changes later and all seems well.

 

I just went back outside cause i thought of something....am i supposed to be able to hear the fuel pump...because i cant hear a thing, no whine at all

 

May be easier to have a second person stand next to the tank outside the car. Will def hear it out there if it is working when your key is turned, but don't try to start, just put in "on" position.

 

OK i cant hear the pump....where is the pump relay switch located on a 92 firebird...ive searched this and all ive found is on the firewall with a red lead wire and a black connector going to nothing,....nothing on my car resembles that...can someone include a photo of a fuel pump relay switch before i buy a fuel pump

thanks

 

Hmm - on mine it's right under the driverside hood hinge on the firewall. Before you go buy a pump you need to do some more checking - there is a pin on the computer port under and to the right of the steering column that you can ground and the pump should run - think it's pin G but double check posts here please so you don't kill anything. When you ground that pin the fuel pump should run and the relay should close. If no pump but the relay closes then you need to make sure the pump has power & ground or has continuity through it with a meter back to the relay etc. If the relay does not engage then you need to look there first. This pin is a test pin specific to troubleshooting a fuel circuit system issue. I would also get a fuel pressure gauge as you will need it to make sure you have the correct pressure once you get the pump running. A Haynes manual outlines all the checks you need to do to be sure you don't just replace parts and not fix the real issue.

 

My guess is that you have TBI, if you were able to pour gas in. Is the "92 Firebird 305" what your working on?

If it is a TBI, then it would have an in-tank electric fuel pump.

You can fold down the rear seat & check the fuel pump plug, under the carper, to see if the pump is even getting power. If it is, the pump, might be dead & need replacing.

 

yea tbi,...

weird thing...the plug under the dash...well where G is supposed to be is empty

 

Frustration is setting in....I bought the Haynes today and the pictures and descriptions of what should be there are not on my car. The G slot on the ALDL is empty, so I cant test the pump, then it said I a supposed to have a fuse labeled FP for the fuel pump....nope....

 

Found out the 91-92 model doesnt have a G pin in the ALDL....solved.
As far as the fuel pump relay...everyone mentions there is supposed to be a red lead wire that I can run 12V to test pump....cant find that either....can someone take a picture of this wire so i know what i am looking for. i am starting to think the 92's are the black sheep

 

Wow - sorry dude - I didn't think they would remove that test pin in 91-92, that made it so easy for me to test mine. I have the 88 GM service manual but now I can't trust giving you direction and waste your time. I do know that when you turn on the key to 'run' the ECM is suppose to turn on the pump for a few seconds to pressurize the system and then turns off until the car is running - then on some cars the oil pressure closes a switch which then engages the fuel pump relay and the car keeps running - kinda like a safety. Is there a way you could see if the relay was being engaged or even if it's suppose to work that way? Do you have a fuel pressure guage you can connect to see if you have any pressure?

You can take out the back seat and the wires to the fueld pump run through the floor there - you could measure continuity through the pump to ground to see if it's open circuit - that what mine was. under the car is the plug through the body to the pump up above the rear axle - might also want to check it's connected and not corroded etc and the measure from the connectior into the tank to be sure. If it's open circuit then I would drop the tank....

 

I already suggested testing from there. Dunno if he ever did though. I suspect not.

https://www.thirdgen.org/forums/post...492-post7.html

I guess my post makes ir appear to be a TBI only test, but it isn't. It is the same for TPIs.

 

checking behind the seat is next...i went ahead and bought a fuel pump relay anyway, and I can hear it click when i turn the key....the only other thing it could be at this point is the oil pressure switch and the pump now right?

 

well if you have TPI, just check the valve with a screwdriver, it should shoot fuel, put a rag or something just incase it is pressurized, once the pressure is released, then go try and fire up da car... then check again the valve for pressure build up, if there's pressure again, then at this point get yourself a fuel gauge so you can check the pressure... if nothing, then you need to find the power source of the fuel pump and go from there, or go directly to the power wire at the fuel pump and perhaps use a splice tab connector and feed it juice... you could also just check all of your fuses with a 12 volt test light, with your ignition in the on position, check all fuses for juice on both sides ...

 

Just make sure you have oil pressure if you power up the fuel pump with some alternative source
If you do have power at the pump to start with and then it dies, pull the oil pressure sender and clean the tip with some varnish remover cause, with the car sitting so long, the sender may be fouled

 

If the relay engages and the pump is working it should be enough to start the car - but then it would die if the oil pressure never comes up. So if the relay is clicking then you need to check for power as close to the pump as you can - if you have power then you need to measure continuity through the pump as you will measure 12v across an open as well. these pump needs several amps and a good 12v across them - if you get soemthing less than say 11.5v or lower I would suspect a shorted pump..