Engine/Transmission (1998.5 - 2002) fass problems

[AOhlmeier]

just installed a fass on my truck now it will not start. a soon as i try to start it the fuel pressure climbs to 19 lbs , the way i understand, it is to high of pressure for the vp. i can take the fuse out of the fass wiring then start the truck and run around and put the fuse in and then it's fine. but i'm running 19 lbs at idle and about 17-18 at wide open. one local shop suggested i put a swith on the fass line running to the bat. and turn it on after the truck has started but this all doesn't seem right after all i have spent ($$) on this premo setup. any advice.

 

[Jefff929]

what version do you have?



The 95GPH I have is 15 to 15. 5 at idle and 14 at WOT.



There is a regulator on the FASS.

 

[AOhlmeier]

suppose to be 95 gph.



now i'm told that the ecm sends the signal to tell it to turn on , so maybe its not suppose to turn on till the truck is running . bad ecm signal maybe need a refash or a catcher,if that will fix it.

 

[JCyrbok]

Do u have the wire harness that runs through a relay that is triggered by the stock lift pump connection. Also with the ground directly to the neg battery terminal.



My FASS will run for about 1. 5 seconds, just like the stock lift pump did, when the key is turned on, then it stops, until the truck is started. Its controlled by the ECM. In the 1. 5 sec that it runs, I dont see anything higher than 3 psi, which dropps, when it stops. Then I fire the truck. If it keeps running it may be faulty wiring ( check it) or back ECM signal. Also swith out the relay with a new one, maybe it is sticking. I carry a couple of spares that I got from Waytek for a couple bucks a piece.



Hope this helps,



J-

 

[AOhlmeier]

when i turn the key to on it run for 2-3 seconds jumps to 18 then bakc down to 0. as soon as i start cranking it jumps to 18 but will not start. its got to be a ecm signal or the relay doing this. i'll try to find another relay locally, but i also heard of putting a lower pressure spring on the outlet of the fass.

 

[RTillery]

Your pressures are about right and the sequence for key on and cranking are exactly what mine does. Has worked fine for 20,000 miles. Where are you picking up your pressure? I plumbed into the fitting at the pump. I left the fitting loose and bumped the pump to push all the air out before I buttoned it up. (What a mess) Is it possible you have air trapped before the injectors? You might have to crack some lines to bleed them if the fuel is actually getting to the pump. Have you set any codes? Keep after her and you'll solve it. Good luck