Crappy fuel mileage revisited

[Paul_]

I filled the tank on the Vic the other day, and I've gone just a tick over 100 miles and the gas is almost all gone. The car is not leaking gas anywhere. I parked it the othernight with a huge sheet of cardboard under it, and no leaks. I do not smell gas either. I replaced the speedometer unit with one that I know the gas gauge works and the results are the same. I'm also not getting a CEL either, so I'm hoping that rules out the O2s. I replaced the fuel filter a week or so ago. I made double sure it was facing in the right direction. The car since then has become slightly harder to start, and the idle seems a bit more erratic. I did check the fuel pressure regulator. No gas came out, just a loud hissing noise which I'm assuming it's supposed to make. I don't know what to do. I'm in a financial situation at the moment so I can't afford O2's or injectors if those are the problems.

[mrltd]

I've had all kinds of codes and no engine light.....

Milage that bad would have to be vacuum to the FPR, the map sensor or some really bad injectors...Timing will also affect milage alot.

[Paul_]

I'll check the computer for codes. I haven't checked timing yet. I'll see if my friend has a light I can borrow. Before that, I'll examine the line running from the FPR to wherever it runs, and I'll try the MAP off my donor car.

[gadget73]

The vac line should go from the pressure regulator right to the vac port at the back of the upper intake, its like a 6" piece of line or something. Not sure what noise a FPR would make unles it was the vac line sucking air and hissing. Do you have a vacuum guage? Might wanna hook it up and see what it tells you. If its low, start checking things for leaks. Those vacuum lines under the intake tend to get pretty nasty with age.

Just curious. have you tried letting the car idle with the cardboard under it? Maybe its got a fuel leak only under pressure, tho I'd think you would smell that. Are any of the plugs wet or extremely black? If one or two are, it might be bad injectors. Handily, you can just steal them from your other car if it ran OK, just replace those O rings.

I'd also agree with MrLTD about checking the codes. Might find something useful there. I might be able to hook you up with a used O2 sensor with not a ton of miles if yours are bad. I'm pretty certain one of mine is shot, considering its actually bent and physically damaged, but the other should be just fine. It was replaced with the engine, about 25k ago.

[88MercWagon]

I was thinking that being hard to start and erratic idle might be the TPS as well. just my drunken $0.02