Engine/Transmission (1998.5 - 2002) My fuel pressure is dropping

[AFoulk]

I have a FASS 150/150 system that I installed this summer, with the factory fuel filter housing eliminated and have about 4,000miles on it now. I also have a Vulcan Drawstraw installed in the factory module, with the one screen cut out and the bottom one left in the pickup of the factory fuel module. This summer I was seeing 20-21psi at all times. As the weather got colder this winter, I was seeing 15-16psi when I start it up in the morning (it sits outside, but I plug it in at night) and once I got up to operating temp. the press. usually came up to 17-18psi. This is ok, I expected this since I eliminated the factory fuel heater. We got some cold spells around here about a month ago (20-30*F at night) and when I'd start it up, press. would be about 14psi, and come up to 16psi once heated up. Now I'm seeing 12-13psi at start up, and I gotta drive atleast 30miles until I'm getting 15psi and thats about as high as it goes. Its doing this even in 45* weather.

Is it possible that my fuel filter is plugging up already? I use 1qt. of 2-stroke and half a quart of PowerServices winter fuel treatment at every fill up in the winter. Also, can the overflow valve on the injection pump fail in the open position? I replaced the pump and installed my fuel pressure gauge (with isolator) about 2,000miles ago. I replaced the overflow valve at the same time, so I'm kinda doubting thats bad already, but I can't imagine that my fuel filter would be plugged up already too. All my FASS system electrical connections seem to be ok, nothing loose or corroded. It sounds like the pump is running just as fast and not any harder than it always has.

 

[Jefff929]

Is it possible that the Draw straw is picking up stuff that has been in the tank all along?

Does your 150 flow more that my 95gph? maybe it stirred up crud from the bottom of the tank.

Have you checked if there is water in the W/S filter?

What would it hurt to change the filters? other than your pocket.

 

[AFoulk]

I guess it could have been, but I didn't really see to much crud in the tank when I had the pickup module out to install the drawstraw. the 150gph system flows more than the 95. I've been trying to find the fuel filters cheap here locally, but I'm not having much luck.

 

[AFoulk]

fixed my low fuel pressure problem. took my gauge pod off to replace the tweeter in it and found mostly air in the line from the isolator to the gauge. The fitting at the isolator had come loose slightly and started leaking. I pressure tested the isolator by blowing into the line with my mouth just to be sure that wasn't bad. Didn't find any fuel in the line to the guage, so I didn't think that was the problem anyways. Now I'm back to a steady 20-21psi.