Changed my fuel filter yesterday and gained .5 psi of pressure across the range.

But today, I hit the old go button and she dropped to 6 psi and then built back upto 11. Either way i have never experianced anything less than 16 psi WOT.

Am I already having problems?? Hope not, this is supposed to be the reliable fix for the unreliable lift pump.

 

could just be some air that pushed its self out ,is it still doing it?

 

Air in the system. It may take a few days to purge all of the air out. Give us a report in a week.

 

If it don't go back up after a few days its probably a weak spring in the pump.
I had the same troubles with mine. I tore the spring out (manufactures recommendation) and put a slightly heavier one in. Now its 22 psi at idle and 16-18 at wot. Before I changed the spring Id draw it down to 2 psi at wot and idle at 18.

Mooseman

 

I had something similar. After checking out everything, it turned out I was low on antifreeze in the FP isolater. Filled it back up and up to 17 psi again.

 

The screen on the end of the pickup tube could also be clogged in the tank.

 

well its back up to 15 psi at WOT....another thing i thought of was the return line to the tank....doesnt the vp44 "throttle" the fuel return based on its fuel needs?? The more it needs the less it will send too the tank?

 

Correct.

Must have had air in the FP guage line. Low FP readings are a common symptom after a fuel filter change.

No problems with the FASS II that I have read about. The spring replacement is the only issue I have read about and it is very rare.

 

well it wont be air in the fp guage line, as i have an electric guage.....

 

could this be my problem?? The VP44 getting ready too bite the bullet, so things ares slowly going wrong...instead of dead pedal?

 

Electric FP guage readings are unreliable. Maybe you should add this to your signature.

 

Well it is reliable so far, as i have tested this with my test guage.....i never rely on a single guage too tell me whether or not something is working.....i always use a back up, whether the guage is mechanical or electrical, nothing is 100% accurate.