I have an '89 Firebird Formula 350, which I have pride in and love, although it's always giving me flak. When I first bought the car about a year ago, I noticed that it reeked like gas back where the gas flap is, and it kind of cut out sometimes, so I changed the fuel filter. It still reeked like gas, and acted like it wanted to cut out whenever I tried to give it just a little gas. Recently, I got it back this winter because a friend rebuilt and beefed up the tranny, and it was great. But now, when I flog on it and mash it to the floor, it tries to kick down and sort of freezes in the act of grabbing a low gear. Also, when it does this it keeps revving out without doing anything until I let off, and then once it straightens out I've practically got to mash it again to go the speed limit. It splutters and barely runs afterwards, and I'm forced to pull off the road. After I turn it off and it sets for awhile, it's fine again as long as I don't give it too much gas. Today it did it again, and the tach read less than 400 RPMs and it idled really rough, trying to quit, while the fuel pump sounded like it was droning, getting loud then quiet then loud again, and the gas gauge was screwed up. When I turned the key off, then turned it forward, the fuel pump didn't prime, and it took several minutes and tries before it did. It's got to be the fuel pump right? Or something in the fuel system? One of my friends says it couldn't be, and I'm almost positive it is. Please reply, it's putting me through hell. Soon six-cylinder Mustangs will be welding my doors shut while I splutter on down the road. Thanks.

 

Maybe you are vapor locking. My gas cap has a small hole drilled in the center of it to prevent it. But my car is a carbed engine.

 

<h1>Dave,</h1>
(That's Big DAVE for the rest of you...)

The ECM will not operate the fuel pump on a restart unless the ignition has been tiurned off for 20 seconds or more. Usually, there is no need, since residual fuel pressure would be enough to start the engine, and as soon as the distributor starts turning, the ECM will power the pump again.

If you suspect a failing fuel pump, get a pressure gauge and connect it to the test port. It's possible that your stalling and poor idle are due to a different matter, but it would be good to know the fuel pressure to be sure. The gauge is cheaper than a pump, anyway. You may just as easily have a regulator problem, and the only way to know is to test the system pressure.

 

I've had the pressure checked twice. The first time it went to about 20, then dropped down to a little below fifteen. The second time, it shot up to about 45 and dropped to and stayed at 40, which I'm told's about right. The rough idle and low RPMs are linked to whatever's doing it, because it only does it when it falls on it's face and won't grab a lower gear; when it's trying to die after I pull off somewhere. But then after it sets a few minutes it's alright. I considered the regulator, and getting my fuel system flushed and injectors cleaned.