5.0stanger

Okay, I have noticed that after running my car and shutting it off my fuel pressure drops down to nothing in about 2 hours. What would cause this? Leaky injector? Is there anything else that would do this?

Also, If I have a leaky injector, would that cause stalling during start ups? I didn't have this problem untill after I put in some 24lb injectors, but it worked fine for about 2 to 3 months, then the hard starting happened. Also, when I had my 19lb injectors in, it would hold pressure.

jwog666

leaking fuel pressure regulator dumping pressure to tank or to vacuum line on regulator, leaking fuel pump releiving pressure back to tank, and of course leaking injectors. i dont know about a stall, usually just one injector is leaking and it will cause a rough startup ( a miss on one cylinder combined with some black smoke out of the exhaust that goes away after a few seconds) your stall could be due to the lack of initial fuel pressure on startup. a regulator leaking fuel into the vacuum line will also cause a rough startup.

run the vehicle, shut it down and pull the vacuum line off the regulator and see if fuel starts to seep from the nipple if so its bad. i have seen more bad fuel pumps and regulators than leaking injectors. hope this helps

AdderMk2

I never had pressure bleed down until i installed an AFPR..

not it drops off if I let it sit... but I have never had any adverse effects from it.

5.0stanger

I have the Kirban adjustable regulator.......I will take a look at it jwog666, that sound like a good possibility. Maybe I will put the stock on back on and see if that helps also.

AdderMk2

I have a kirban as well... and it just bleeds pressure a little...

but like I said. It never gave me any probems.

5.0stanger

Yeah, I know they are good, but I am just looking into every option. I just went out and smelled the vacuum line and it smelled like gas. I'm gonna try and switch it back to the stock one and see if it gets any better.

5.0stanger

anyone know where to get the rebuild parts for the Kirban regulator?

AdderMk2

just disconnect the vac line and see if fuel comes out the top of the regulator

silver91gt

its normal, I put in an aeromotive fuel system with a large regulator and pressure bleeds off as soon as I shut it off.
this will have 0 adverse effects because the fuel pump supplies the fuel when its running, who really cares if it holds pressure when it isnt running.

5.0stanger

Well, I swapped out to the stock FPR, and low and behold, the car fires right up with NO stalling....hmmm

I still leak down fuel pressure, but if it runs good, I don't care.