Thread: 2000 GTP Fuel Delivery Problem

Originally Posted by addeible

This is a long story but please stay with me, I REALLY need some expertise.

About three months ago my car started running poorly when in gear but at a stop. It also performed poorly when my foot was off the gas at high speed. It threw a p0440 code about a week later for a purge solenoid valve. After replacing it, it ran a little bit better, but began to throw cylinder misfires. I figured the bad sensor fouled out the plugs which I had been meaning to replace anyway. I put ACDelco wires and Bosch premium plugs in it and it no longer threw codes. It still runs poorly and will even die when I am at high speeds and I apply the break unless I drive two footed and keep my foot on the gas a little bit. I have to take out the plugs and clean this black film off of them every few hundred miles or it will misfire in the second cylinder. If it sits for a couple days, it starts smoking at the rear exhaust manifold (near the second cylinder?) and smells of burning raw fuel. It will also smoke out of the tail pipes and smell of raw fuel. I have been told that it may be a bad carbon canister in the rear of the car, or perhaps a vacuum leak. I keep replacing various sensors only to return them because the performance has not changed. The only sensor that is new is the PSV. Again, it is throwing no codes besides cyliner misfires when the plugs get gummed up.

Any ideas on things to check out would be greatly appreciated. At this point my next guess would be to tear apart the injectors and check for leaks but that would be entirely new to me.

On a slightly less important note I took it to a mechanic who charged me $240 and all he did was put new plugs in it, telling me I had gotten the wrong kind which turned out to be untrue. So I'm done with the notion of taking it to a mechanic as that was both the first and the last time I don't do it myself.

This sounds like my car, only I also have code P0128.

Once the car is on, all I can smell is gas and then when my boyfriend punched the gas (car was in park still) there was a big cloud of bluish-grey smoke. Now we're trying to figure out what the problem is. Did you ever come to a solution for this and did you do a drive cycle to see if the codes came back?

Update...I parked the car for the winter as I am a college student and havent had time to deal with it. Now that it is spring time I am still trying to get it running right. It seems a main cause of my problems was leaking fuel injectors. The fuel would collect above the block and eventually run on to the exhaust manifold. honestly it is a wonder I havent had an engine fire. I have replaced the MAF, FPR, PSV, plugs/wires, as well as a full "service" of the fuel injectors (new upper and lower seals, mesh filter, and retainer clip). I installed them today and it still seems to be missing on a cylinder. The fuel no longer collects on the top of the block which is a good sign. I am going to clean up the spark plugs tomorrow as they may be gummed up from the excess fuel/long sitting time. I will report back if that makes the difference. Fingers crossed.