Two weeks ago, I filled up my tank at the same Shell station I've been using for years. Immediately after that my car started running like crap, it would drive normally under part throttle, but as soon as I floored it, major hesitation and stumbling.

I had an appointment the very next day to change the spark plugs, so I had the mechanic drain the fuel tank, as bad fuel was the #1 suspect. That turned out to be a waste of $50, because the issue was still there after we put fresh gas from another station in the tank, and test drove the car for about 5 miles. The mechanic had another appointment, so I agreed to drop the car off later that night, after I picked up a rental.

On the way home, the engine ran noticeably smoother, so I went for it and lo and behold, it pulled like there was no tomorrow. Elated, I though maybe we just didn't drive it enough, all the way home I kept testing the acceleration and was not disappointed in the results, that is, until I stopped and refilled the tank at a different station, the problem was back as soon as I pulled out of the station, I attributed that to stirring up whatever crap was leftover in the tank from the shell gas. As fuel was used up, the car was back to running as usual, so I was sure the contaminant was all gone.

I filled up again yesterday and the problem is back. It only seems to happen on a full tank, so I'm wondering if it is some sort of venting problem?

Does anyone have a schematic of the fuel system? I am loathe to go the dealer without some knowledge on the system.

Thanks,
Marlon

 

Ethanol seperation maybe . U might have a glob in there .

 

Malakas: It's on the 3rd tank, so I don't think so.

Schematic, anyone?

I lost my bookmark to the site where you can put in your VIN and see all the options on your car, and get part numbers. If anyone has that, please post the link here.

Thanks,
M.