I checked my fuel pressure at the schrader valve today. I got 41 when I turned the key to on and 38 at idle. I then let it sit and after 1 hour it dropped to 31. Is that an acceptable drop in pressure? I pulled the injector rail and it had no leaks. My FPR has no fuel in the vac. line. I have been trying to narrow down a miss at idle and have replaced everything electrical, so I have been leaning towards a fuel related problem. Car is very rich and will not pass HC on emissions.

Any suggestions?

 

that seems about right for a drop in pressure after an hr or so
it should take about 4hrs to completely drop off
mine drops off to 0 immediately after the car is shut off and only holds about ~37psi at idle
i've narrowed mine down to the fuel pump or a hose in the tank that is prone to developing a hole in it

have you checked the injectors to see if they are leaking?

 

Have your injectors cleaned professionally either through the rail or off the car. Although off the car is better since they can be checked for flow at that time.

Have you done any ignition work lately?

Have you checked exhaust back pressure?

Can you scan the engine to see what the sensors are doing?

Have you checked the TPS?

 

All ignition components replaced, problem persisted.

Not sure how to check for exhaust backpressure.

Scanned with freescan and all readings were good.

TPS is new.

Good vacuum as well.

Also, miss is alot worse at idle in gear with my foot on the brake.

 

maybe it is your Pcmforless tuning, i have heard a few ppl have problems develope, can u get it flashed agin for free?