2002 Explorer 4.6L long crank time to start

[RonD]

If pressure climbs while cranking then I would have to say fuel pump is being turned on which may be normal for the computer in your model.

But the drop in pressure seems to point to the check valve/back flow preventer on the fuel pump, or a split/leaking line in the fuel pump system in the tank.

Your MPG would be severely effected it this was a fuel leak outside of the tank.

 

[ab_slack]

I'll have to fill it and see what the MPGs are. I track every fill, but this problem showed up just before the last fill.

I tried the WOT test and didn't start, didn't sputter or anything. Then I repeated the test but first did a key on/key off to charge pressure and let bleed down a few times so if it were dumping fuel into the manifold it give a better chance to catch but again the same result.

I think you are right about the full pump and fits adsm's probable cause.

*yuck* doesn't look like a cheap fix.

 

[ab_slack]

Never got any real fuel economy check. I've put in a few tanks but with all the snow and lots of idle time while warming it to clean snow off I don't know that the low 12mpg I was seeing means anything.

I did bite the bullet and went with the odds since everything else seemed okay and put it a fuel pump assembly. The fuel rail pressure drops about 8 PSI when I stop engine but then holds at 57 PSI and only moves very slowly. like 2 PSI in 5 minutes. So this corrected that symptom.

I do notice when I turn the key to run that after sitting all night pressure doesn't come up immediately. So pump doesn't appear to pressurize the system with the three second run. It starts right up. Haven't experienced long crank yet so far so good.

I also noticed when it did start, pressure stayed low and built slowly to 65PSI while idle.

Previously, when it cranked long time it would show no pressure, start as soon as it had just a little, but then jumped up to 65 PSI much quicker.

So I don't know if there is anything to read into that. With the warmer weather and some long drives this weekend (things that made it hard to start) I should find out if the starting symptom is resolved