Fuel pressure stuck at 52lbs and TPS

[white-t-type]

When my car is running with the vacuum line on or off the fuel pressure stays at 52lbs. I have an accufab fuel pressure regulator, when I back the srew out of the top the fuel pressure does not drop. Also thought I would mention that it does not change even when you put the vacuum line back on. Any ideas? Also thought I would throw in the lowest reading I can get on my TPS is 4.69. Car is definately running rich. I took it for a short drive and the plugs are completely black, o2 volts were in the high 500 to low 600's at idle and in the upper 700's at normal driving. Giving the car more than half throttle results in fouled plugs. Just looking for some ideas.

 

[OneQuikSix]

Assuming you don't have any massive vacuum leaks elsewhere, I'd be inclined to think you had a bad regulator.

 

[novaderrik]

could it possibly be a blocked or kinked return line?

 

[87GN_70GS]

Or could be your fuel pump is overwhelming the regulator and/or return?

Does the fuel pressure rise if you apply positive pressure to the top of the reg?

 

[notacarlo]

Or the guage is faulty.

 

[DailyDrifter]

could it possibly be a blocked or kinked return line?

+1

 

[Clark6]

I thought the blocked return line will make the fuel psi go sky hi because its building pressure after the regulator & the pressure would have to go somewhere which would make the gauge @ the fuel rail climb i may be wrong though

You can pinch the return & psi should rise at the guage if not try another regulator that someone owns.

 

[WSLN 6]

How on earth does the car idle when the TPS is that high? Where are you measuring the voltage from? (or is it scantool?)

 

[Underboost]

Assuming you don't have any massive vacuum leaks elsewhere, I'd be inclined to think you had a bad regulator.

+1

 

[white-t-type]

How on earth does the car idle when the TPS is that high? Where are you measuring the voltage from? (or is it scantool?)

Sorry I have been having computer troubles, this is the first day I have been able to get on. TPS #'s are from the scanmaster, on the volt meter plugging into the second wire it reads the same number. I will try to pinch the return line as well as turn the knob in to see if it changes anything tomorrow.

 

[novaderrik]

I thought the blocked return line will make the fuel psi go sky hi because its building pressure after the regulator & the pressure would have to go somewhere which would make the gauge @ the fuel rail climb i may be wrong though

You can pinch the return & psi should rise at the guage if not try another regulator that someone owns.

if the fuel can't return to the tank becasue of a kinked or plugged line, the fuel pump will bypass internally and maintain whatever pressure that happens to be in the line.

 

[tonys87]

i also have the same problem you do except mine is stuck at 43psi..i changed the gauge and sent the regulator out to get rebuilt and no luck. i also was told that it might be a kink in the return line which i have not found yet..good luck

 

[frank700]

Kind of having the same problem. After car gets into boost fuel pressure will not come back down. Changed out fpr same thing now going to change fuel pressure gauge. I'll let you know.

 

[white-t-type]

The return line looks fine, I could not find any kinks. When I turn the bolt in on the regulator the fuel pressure will rise. I only brought it up to 60psi and that was with the bolt turned a little over half way in. I changed the gauge to another one that I had and it showed that I had 48psi. I am ok with the fuel pressure but the tps has me stumped. Could it be deffective? I bought it new maybe 6 months ago.

 

[WSLN 6]

If the TPS doesn't change voltage when you measure it right at the sensor, it has to be bad. Do you have a good 5 volt (or close) on the one wire and a 4.62 on the other?

 

[white-t-type]

If the TPS doesn't change voltage when you measure it right at the sensor, it has to be bad. Do you have a good 5 volt (or close) on the one wire and a 4.62 on the other?

Been messing around with it a little today and now have 4.48 in the middle for the tps and 4.88 for the bottom wire which is close to 5 volts.

 

[WSLN 6]

If you are holding the throttle blade wide open and measure that, it's fine. But with the throttle closed you should have .42 volts or so. If not I would try another sensor or collect warranty on the one you have.