i have a 91 camaro with a 305. I have replaced the following: fuel filter, plugs & wires, cap & rotor,EGR, and throttle postion sensor. If you hold the gas down a little it will stay running but as soon as you let off the gas it just cuts off. It's not making any noises and while you keep it running the engine sounds good(no skips or vibrations), and once you get it moving on the road it will go fine but its lacking in the power department. It feels like its running out of gas. I've run the codes and keep replacing parts but with no improvement.PLEASE HELP. im a single mom with not enough funds to put it in the shop. this car is my baby, cant live without it, any advice is appreciated!! thanks!!

 

you're a girl so I have to ask this question. Are you sure you have a carburetor? 1991 camaro RS didn't come stock with a carb. Your 305 may be TBI. If thats the case you should post this question in the TBI forum.

 

you were right.. it is TBI... i was reading a post under carburetors.. didnt realize that was where i posted, sorry.

 

no need to be sorry. just didn't want you to be wasting your time here.
(i'm sorry about that girl dig. there's a few guys around who can't tell the difference.)

 

We'll just move it over the TBI and pretend it was always there. . .

 

check fuel pressure? possible fuel pump?

what codes it throwing? take car to auto parts store and have them connect to ALDL and see what codes are stored.

 

It sure is a fuel problem...or maybe the ECM

 

the first code was for EGR, and we changed that. then it was for the TPS, and we changed that. and yesterday it was code 23.. for the idle air control valve, changed that and still no better. code 23 is still coming up. im at a loss.. (aside from dropping the gas tank which ive never attempted on my own) i dont know where to look next

 

well im still having this problem with my car... after a few days of runnung fine it started acting up again. I had to constantly pump the gas pedal to keep it runnung enough to get home. my 5 brothers and father have all looked at it and cant figure it out. we can fix it, but cant diagnos the problem. the majority seems to think its not the fuel pump, it is getting gas through to the injectors but it still stalls out. could this just be the ECM?? or the oxygen sensor?? i dont know much about the oxygen sensor, but ive been told i can unhook it and still drive, but if thats true how could it being bad affect the car???please, running out of time and money.... ANY SUGGESTIONS??????

 

You need to check the fuel line feed pressure. A dying pump will give you the impression that there is enough fuel. A dying pump can produce 7psi of fuel which will allow the engine to barely run as well as produce a nice fuel cone out of the injectors. You can rent a fuel pressure tester. If you see anything less than 9psi it is time for a new pump. This is a quick and easy way to rule out a fuel problem.

 

I agree with a possible fuel pump prob. The Caprice acted the same way when the pump died.

 

So did the problem ever get solved? I have the exact same car as your's... with the exact same problem. Just wondering if you ever came to remedy the problem.

 

Id say its possibly a dead fuel pump as well, especially if its hard to keep it running when cold. When the engine is running lean, it will still run ok, but lack power.

Bad news that if its the pump, youll likely have to have a shop do it unless you want to drop the tank. Real PITA in these cars.

 

tell ya what, I hear you.. I already had a shop replace the fuel pump and then they tried to charge me for a ne Sending Unit assembly for $700... parts only! I said screw off and got the car towed back to my house.. At this point, the car wouldn't start. I ripped the fuel tank off myself and made sure everything was installed correctly, while, with the help of the haynes manual, I found a few things messed up. ANyways, put it back together, and I replaced the fuel pump relay. After this, the car starts up as beautiful as ever in park, however, when driving it, it still has the same problems, I.E.:.. having to hit the gas a lot to get it around... I keep thinking the sensors...any help really appreciated!

 

Long story short. I never found anyone to change the fuel pump for me, since I couldnt afford for a shop to do it. Still runs the same, I drive it daily 3 miles to work, gets me there. But it has been over 8 months... if it truly is the fuel pump, would I still be able to drive it after all this time?

 

I also have a 1991 RS with the same 305 TBI motor and its having the same problem. The car has new cap, wires, plugs, rotor, and EGR (had a code 32 but got rod of that), car idles with like 12-16hg vaccum steady, everything was going good. Then one day when starting the car I start to hear a loud whine from the fuel pump, then all these problems began. Car starts a little rough and sometimes when applying throttle the car will seem to just bog out. But sometimes it works fine. Sometimes when letting off the throttle the engine will hesitate.

The best thing to do when suspecting a fuel problem is to test the fuel pressure, this way you can prove it out. Its usually a divide and conquer method, you'll test the pressure somewhere between the pump and the injectors, usually near the fuel rail in the engine bay. If the test is good you move towards the injectors with the possible culprits being the fuel pressure regulator or the injectors themselves (or what controlls the injectors). If its bad you move towards the pump with the possible culprits being the pump itself or the things that control the pump (fuel pump relay or distributor pulse), a clogged fuel filter, or a clogged pickup/line. When you turn the ignition on the pump should prime. Check the pressure by the fuel rail, should be between 9 and 13 psi for these 305 TBI cars. After the pump primes the pressure might drop a little bit but as long as the ignition is on (making the fuel pump on) the pressure should hold steady between 9-13psi. I'm pretty sure when I do this test it will fail. I hope I'm lucky and its a clogged filter.