What The Hell?

[steveissteven]

What could cause the following symptom?


I have a 1993 Ford X-Plorer Sport....

When the fuel gauge reads 1/4 tank or less / vehicle runs great. (Full Power and very fluid... almost new)


When the fuel gauge reads more than a 1/4 tank, however, vehicle loses power, idles kinda funny (sounds like it has a slight sputter at the tail pipe), and just laks overall performance.


I agree, pretty strange. Any ideas???


The following have been replaced and or repaired!


1. New VSS (vehicle speed sensor)
2. New tranny
3. New intake manifold gasket replace
4. New radiator / hoses / water pump / thermostat
5. New injectors (about a year ago)
6. New MAF
7. New brakes
8. New Electronic ignition system
9. New FPR (Fuel Pressure Regulator)
10. New fuel pump
11. New O2's
12. New Catalytic Converter
13. New battery
14. New battery cables
15. New plugs and wires
16. New TPS (throttle Position Sensor)
17. New ECT (Engine Coolant Temp Sensor)
18. New Idle Control Valve
19. New Fuel Filter
20. New Air Temp Sensor


Your thoughts and ideas will be much appreciated.


Thanks....

 

[dbarale]

???? ????
Could it be a clogged or pinched fuel return line that could cause a problem with the FPR or the fuel pump.
I would have the fuel pressure checked if not already done...

 

[jimmiecakes]

Is this like a "night and day" kinda thing where one minute it's great and the next it's crap? Or is it a "the lower the guage gets the better it feels" thing?

Enquiring minds want to know....

 

[yob_yeknom]

Okay guys, that charcoal canister thing I've read about on here before, doesn't it have something to do with the fuel return?

Just throwing in another idea.

 

[jimmiecakes]

Okay guys, that charcoal canister thing

Not with fuel return.... it traps fuel vapours from the gas tank and then burns them in the motor while you're driving. There's one line from it to the fuel tank vent and another (with a solenoid valve) that goes to intake manifold vacuum. This valve is controlled by the ECM and is only open at certain times - sorry, I'm not sure of the programmed strategy.

Steven could check this line to see if raw gas is present when the problem is occuring but that's not where I was actually thinking of going with it. Very good point though.

 

[yob_yeknom]

Originally posted by jimmiecakes
Not with fuel return....

Oops, my bad!
That was the only thing I could think of dealing with the fuel system that hadn't been metioned or replaced already.

Definitely let us know if you figure this problem out. I'm completely stumped as to what it could be.