Fuel pump pressure was 30lbs but when the rpm was increased, it did not increase the fuel pressure to 37lbs as per FSM specs. What are the ramefications if any because of this? Thanks

What fuel pressure do you get when you disconnect the vac line to the FPR?

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KHGZ31JAMG

Will check in tomorrow with the numbers. thanks

Forgot to mention it but I suspected fuel pump was the culprit because of hard start when engine is hot.



Edited 1 time(s). Last edit was 2008:08:14:20:45:49.

If you have 30 psi on a hot start you should be fine, what ecu codes do you have?

don't know if this helps, but i see that you are having hard, hot start issues? My 86 n/a did the same thing and it turned out to be the temp sensor on the FPR. Just a thought, but i agree with Red.. 30 lbs is ok.

Here's another thing I noticed. When I turn on ignition and let fuel pump operate until it kicks off, car will start with no problem. So what's my complain? The old lady don't allow the fuel pump to kick off before starting. She'll keep cranking and cranking before she concludes it will not start. My question; what's happening with the fuel in the fuel rail when engine is turned off? The fuel pressure regulator should maintain proper pressure so the fuel in the rail remains there, right? The FP solenoid works fine. What you all think?

I forgot when I changed the FPR but I'm beginning to think it could be the problem?

Tell your old lady to let the fuel pressure build by turning the ign on for 15 seconds and then going to start. If she does not get it dump her.........it is perfectly normal for pressure to drop off over time, that is why the pump is energized automatically for 15 seconds for starting.

The pump will prime for 5 seconds.

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KHGZ31JAMG

Geez, I am bad, 5 seconds is right..........

Mister T, did the test with vacuum off the FPR. Reading jumped from 30 to 39lbs. Is it safe to conclude, FPR is the problem? Thanks

no

Please tell me what's the problem? thanks

use the FSM

^@#$%&

Problem is your old lady, tell her to let the pump prime or else she can walk next time and your having nothing to do with the car, if she doesn't listen take her to obedient school.

I used information provided on this site to analyze my fuel system: [www.aa1car.com]

"Safe to say it is NOT the fpr." Norm K.

Norm,

Why is it that you are always quoting yourself??

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1985 300ZX n/a

See my Z project

The gist of the question was why at idle the pressure is 30lbs which is normal but as the rpm increases, the fuel pressure did not increase but stayed at 30lbs. Fuel pressure did not increase or decrease!

"Fuel pressure should decrease as vacuum increases," as per FSM.

The FSM does not address why they were no changes to fuel pressure when rpm increases. So for this reason, I'm asking anyone who had this problem with a definitive answer! thanks



Edited 1 time(s). Last edit was 2008:08:17:10:50:17.