Fuel pressure not holding

[NvgtrWiggles]

Hi there. First post here. I've been having some hesitation issues in my '93 Ranger. I've done a leakdown test, and the fuel rail does not hold pressure. So after checking the FPR, I've narrowed the problem down to either leaking injectors or a bad check valve.

I'm having trouble determining which of the two it is. I've tried pinching off what I believe to be the return line (I could very well have pinched the wrong line) to see if it was the check valve, but no dice. This leads me to believe it is the fuel injectors leaking.

If anyone could give any additional insight towards my problem, that would be great.

 

[RonD]

After shutting off a warm engine, remove the air plenum(big air tube from air cleaner to intake) from the intake end.
Wait a few minutes then open the throttle plate and smell for gas, if an injector is leaking you will smell the fuel very easily.
And if an injector is leaking MPG would be down and you would notice it, also could get Rich Code from computer.

Check valve leaking won't effect MPG.

 

[NvgtrWiggles]

I'm getting a solid 23 MPG with no CEL. My guess points towards the check valve then. Would that cause some hesitation at low rpm?

 

[adsm08]

Also, what kind of loss are we talking about? Return-type systems are allowed quite a bit of loss.

 

[NvgtrWiggles]

I'll get 30 psi measured at the rail and it'll drop to 0 in about a minute after I turn the vehicle off.

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[Mark_88]

Aside from probable fuel delivery issues...you may also have a stretched throttle cable...check for play in the pedal and take up the slack as needed...it will give you instant response again as well as WOT...

I recently found this with a 1998 Mazda B3000 owned by a friend...hers only took two zip ties but it brought her pedal response back to normal...no hesitation...

>>> Check for zip tie fix or similar as this is the standard fix...

Sorry for the interruption...back to our regularly scheduled tech help...

 

[RonD]

yes ^^ good call Mark_ 88, throttle cable is very common issue on older Rangers.

If you want to double check before pulling the fuel pump you can remove the fuel line from the rail and plug that line, turn on and off key 2 or 3 times, wait a few minutes and slowly remove the plug, if no pressure then fuel pump needs to come out.

 

[NvgtrWiggles]

Pedal has no slack. I zipped it a while ago.

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