What is your Fuel Pressure in PSI?

[searcherrr]

What is your fuel pressure in PSI at IDLE and during CRUISING or REVVING the engine?

What is your fuel pressure when you remove the vac line from the fuel pressure regulator?

I'm not interested in what the pressure "should be" (cause I already know), but what people have actually observed on through their own tests on their winny.

I realize not many of you will have an answer for this because its rare to purchase a fuel pressure test gauge, but thankfully our Windstars include a fuel pressure test port on the fuel rail. On my 1995 its on the left of the intake manifold if you are facing the engine from the front of the vehicle.

I am still chasing an issue where the van tries to stall every time the A/C is turned off (or really every time the radiator fans cut off) and while I have unplugged the fans and the engine does not try to stall in this condition I obviously can't leave the fans unplugged. I am also apparently getting HALF the MPG I should be and there is NO CEL. It could still be electrical, but my senses tell me its fuel related and there isn't much to the fuel system besides the filter, pump, and FPR.

If anyone doesn't know and wouldn't mind checking for me I may even be able to arrange shipping you my fuel pressure test gauge so we can get the answers I need. I'd ask if we do that though that you digital video the gauge as you take the pressure readings through the conditions mentioned above.

Thanks to all!

[tomj76]

When I checked mine it followed what the book says. That applies to both with and without the vacuum line.

Is it possible that there is some kind of drag on the engine/transmission that is causing this? After my transmission failed and was replaced we went from 15 mpg to 22 mpg. Are the RPMs at a certain speed indicating that you're getting into overdrive? Can you feel the TCC go into lockup?

[searcherrr]

Originally Posted by tomj76

When I checked mine it followed what the book says. That applies to both with and without the vacuum line.

Is it possible that there is some kind of drag on the engine/transmission that is causing this? After my transmission failed and was replaced we went from 15 mpg to 22 mpg. Are the RPMs at a certain speed indicating that you're getting into overdrive? Can you feel the TCC go into lockup?

What was your psi readout when you tested it? Was it just at 30psi the whole time and did it ever seem to variate between 29-30psi? or did it jump up in a range?

My tranny is rebuilt about 8k miles ago I believe. I didn't notice the MPG problem until after the new engine was installed which was installed after the new tranny. I ran around for a while on the new tranny before putting in the new engine.

Currently I'm getting 10mpg in town and 17 mpg on the highway and these figures are very accurate. I just took a trip and tested it. Overdrive is definitely getting utilized and besides the problem I've been trying to figure out (almost stalls/stumbles at ONLY hot idle when in park or in drive at idle when A/C is off after radiator fans turn off) the van drives like a dream and sounds just as it should (very smooth running) except when I turn off the A/C and the fans turn off.

[searcherrr]

bump

[searcherrr]

Wow, I must be the only DIY guy in the world that owns a fuel pressure test gauge. Nobody?