Fuel pressures

I just got my BBK gauge on the schrader valve and wandered what the correct fuel pressures are. What should the fuel pressure be at idle? When key on engine off? When shut off? Mine at idle is running at 32psi. Key on engine off it is at 38psi. And when it is shut off from idle it jumps to 38psi, then almost 50psi a half hour later, then three hours later it is at 10psi, then eventually at 0psi. Is this right or do I have something wrong.

Thanks!
Shane

Well, every car is going to be different. The only way to really measure fuel pressure is with the vacuum line off the regulator and the car idling. Every car is going to have a different measurement of vacuum so it is hard to say what it is at idle. But it should be about 38 - 42 with it off.

Engine heat could cause the fuel in the rail to get hot after shutting the engine off. That would also account for the temporary pressure increase you are describing.

Your fuel pressures sound about right to me.

David

Cool! Thanks guys for the responces. I needed to know this info to figure out why when I try to start up my car it stumbles and dies. Then when I turn it over for a second time it runs fine. I thought it could have been a fuel pressure regulator or injector going bad. The next thing on the list of possible calprets is the crank sensor. I had installed a new one in the spring when I did my ballencer. Ever since then I have heard a sound kinda like the crank sensor was rubing the timing peice that goes on the back of the ballencer. It even kinda looked like it on the inside of the peice. Could this be my problem and if so is there a way to replace the crank sensor and move the timing peice without removing the ballencer? Thanks for all of the info.

Shane