96 maxima - car starts great when cold or hot (with-in an hour of shutdown)
but when starting about 2 - 3 hours after shutdown it cranks quite a while
before starting . Once started it runs great and gets around 26 mpg.
I put a fuel pressure gauge on it today: key on engine off -pressure was
quite low (thought gauage was bad) , at idle pressure was steady at about
32 psi, But when I turned car off the pressure dropped to zero in less than
1 minute . Suggestions ??
By the way I previously replaced ects and it had no effect.

 

I would suspect the fuel pressure regulator at the end of the fuel rail.

 

had that problem after putting in another FPR

 

What problem did you have before the FPR?

 

I did some more pressure checks.
- about 31 psi fuel pressure at idle.
- pressure jumps about 10 psi when fpr vac line is removed.
- pressure goes up to 43 psi when I pinch the fuel return line shut.
- pressure dropped just a few psi when I turned the car off (with return line pinched)
over a five minute period.
- pressure dropped rapidly as soon as I removed the pinch pliers from return line.

1.) Still sound like bad fpr ?
2.) Ease of fpr replacement ? It's kinda right there, but after 14 years will it be super
stuck and if so ,whats the best way to get it out ?

ps - I also sometimes have a slight knock on acceleration which I assume is due to
the lower than spec. fuel pressure. Make sense?

 

engine coolant temperature sensor.

 

You might want to check for a KS code, perhaps that's the real issue.
As for the FPR, I checked the FSM and it said that the fuel pressure decreases as vacume increases. This implies that with no vacume the FPR should close and at least minimize a drop in fuel pressure. It seems to respod normally otherwise but perhaps it's not sealing well enough to maintain rail pressure with the engine shut off.

 

+1

And a knock sensor is not going to have any impact on cranking or starting.

Have you checked to see if you have any codes at all?

 

oh i dont know if he edited the OP or I just didn't read it but it says he replaced the ECTS.

the symptoms sound identical to mine. It would start when it was dead cold, and it would start if it was warm and hadn't cooled off too much but if it was anywhere in between it would be LOTS of cranking.

are you sure you replaced the right one? there is one for the temp. gauge right next to it that won't make a difference to anything if its replaced.

 

Chillin - Yes I replaced the right one a few months ago. I had replaced the other one a few years ago when my temp gauge was erratic.
I'm pretty sure it's a fuel issue, just trying to determine if it's a bad fpr or leaky
injector(s), without replacing anything that's not absolutely needed.

 

That suggestion didn't have anything to do with the starting issue but simply the comment by the OP that that said: . No good can come of a "knocking" situation under any circumstances.

 

I have a similar issue in the winter time. People always told me it was fuel related. I've done everything cheap so far that the only thing left is the fuel system. I think your gut is telling you the right thing

 

*Update* - I replaced the fuel pressure regulator about a month
ago and this has indeed cured my problem ( long crank time when
engine is still warm ( maybe 2 hours or so after shutdown))