Engine/Transmission (1998.5 - 2002) FASS and PCM signal

[MKizziah]

Just put in a FASS to replace dead LP. I ran it to the Stock Filter and put the FP guage on the output side banjo fiitting on the Filter. Here's what going on.



Turn key on the FASS fires up for a few seconds. . FP guage shows 1-2 lbs. WHen I start cranking after about 10 secs. the fuel pressure rises to normal 15lbs. Once and if it starts the FP guage stays @ 16 drop to 15 WOT.



Is this normal the normal signal from the PCM for the lift pump??

I would think when the key is on the the fuel pump signal should stay on. . til you turn the key off.



Anyone have any thoughts ?? bad PCM ??? weak spring deal I read about some of the FASS??. . SN# up around 2800. . think it be fixed by then.



Trying to avoid a new VP44 if possible

If I have to replace the VP44 any recommendations ??? best Price ???



Thanks in Advance



Cheers,

Matt

 

[dpetre]

I have a FASS with a similar set up. Bump starter and pressure will go to 15. Just turn on key and no pressure. I am guessing that is normal. Even with old lift pump I had to bump starter after changing fuel filter. I change to the FASS but my injector pump was on the way out and it had to be replaced. Mine had 50K on it so it was under warrenty.

 

[MKizziah]

Normal??

I'm at 102K, your lucky... lol. So thats normal for the FASS to not come up to pressure key on ?? After VP44 RnR your truck fire on the first bump ??



Thanks,

Matt

 

[Tcolesanti]

Thats the way they all work, turn the key on and it will run for something like 3-5 seconds, bump the starter without starting it and the pump will run for something like 25 seconds. As long as it is producing pressure while the truck is running, your fine.

 

[Moose Truck]

Lift Pump and ECM

Tcolesanti is right. The LP Runs at key on for 3-5 without cranking it. If you Bump the starter the LP runs for about 30 Sec. If you get 15 PSI WOT, then you are Golden!!! :-laf Moose00

 

[MKizziah]

Golden

Thanks for the responses guys . . ya'll rock!!



I'll sleep better knowing my FASS and PCM are working!!



This thing has so much power!! busts em loose at 25 in a curve in 3rd . . and it's a dually!! never go back to a gasser!!! IF I could just get it to start everytime I would be GOLDEN !!! LOL





Thanks Again,

Matt