OK here is the thing. My fuel pump took a dive about two weeks ago, no real big deal besides having to take the fuel tank down. Anyway after replacing the fuel pump the car won't hold an idle. It will start, rev up for a sec and then just die or run real choppy. I check the output of the pump but not the actual pressure. The manual said it should pump about 1/2 pint in 15 sec and mine pumped over a pint. Am I wrong to think that this should be enough. I am new to this TPI thing. Only had the car for about 6 months.

1988 pontiac firebird
305 5.0L
TPI

I cleared the codes from the ECM and started new and the only code that came up when I got it to run long enough was 36 which says MAF,burn-off or ECM.But I figured that it was not running right so that may be wrong?

I have checked the timing after I unplugging the EST wire and that is set right.

The car ran fine before I changed the pump.

Could the pump going out mess up some sensor or something?

Any thoughts?

 

OK a little more on this. It seems like it is "flooding". It has a running rich smell. When it idles if I step on the gas it starts to sputter, sounds like it wants to backfire but if the rpm's get high enough it will run good for awhile but then slowly die.

Can the fuel pump have to much pressure?

I can't believe that just changing the fuel pump would start all this.

 

check your fuel pressure, the thing that regulates rich/lean mixture is your MAF, and if its not properly working then its gonna start throwin fuel in *****-nilly. but before you go replace the relay, check your fuel pressure, it should be at like 38-42psi.

 

Well I will try anything before replacing the MAF sensor. I think I could replace the engine for less lol. And would that go out just by replacing the fuel pump? But I will get a pressure guage and check the actual pressure.

 

Ok yesterday I got a hold of a pressure gauge and tested the pressure. Well to my disappointment there was only 20psi.

Is there a high pressure fuel pump?

Is this one just defective?

Is there any other way to see if it is really the pump and not the fuel pressure regulator. I just don't want to have to pull that damn tank again.

 

just make sure they gave you the right pump. the one for tpi and not tbi. look @ the parts store reciept. cross the fuel pump part# online. or post it on here.

it could very well be a bad pump. you should have close to 40 psi when you prime the pump. to check if the regulator is at fault pinch the return line closed. it is the smaller 5/16" line.

 

Well I think that may have been it. In calling around and doing a little more investigating I found out that the one I was sold was for the "E" engine and not the "F" even tho I had specified that at the time of purchase. Come to find out that that company only lists one for both. I have not installed the new one yet as I dread having to drop the tank again. But I will more than likely do it tomorrow.

 

check ur fuel filter too

 

yeah a vin "E" (TBI) pump won't run a tpi very well at all. if anything order it for a vin "8" (350 TPI) just to be sure (it uses the same pump as a vin "F" 305 TPI). they always confuse the 2 305's as being the same and using the same parts.

 

Oh man, sounds like it's time to slap the s h i t outta the parts guy! That really sucks to have to drop the tank and do it all over again. I feel your pain bro.

 

Well that was it. The damn fuel pump. Got it back in and it started right up with no problem and runs great.

Thanks for the help and the suggestion for the parts guy.

 

I hope that doesnt happen with my 91z the pump gets changed on fri.

 

No problem on the suggestion for the parts guy! I remember years ago I needed a new throwout bearing for my 4 speed Muncie in my 69 Camaro, and the stupid parts guy sold me a throwout bearing for a 3 speed trans, which was too tall so I couldn't get the clutch adjusted right for nothing. I was so pissed that I had to pull the trans again. I could complete that job in under an hour these days, but back then, it was a major undertaking for me. I learned a long time ago to make sure to double check part #'s and their application, which is the exact advice I'll give to 92RS365HP. Just make sure it's the right one! I'm running the Walbro 255 TPI pump in my TBI car, which is no problem since the factory regulator keeps the pressure in spec. Unfortunately, it doesn't work the other way around (TBI pump in TPI car).

 

got it changed and it run wonderful,but..........now I have a prob with blowing brake light fuses any thoughts???