installed fuel pressure gage. changed tunes.

[dadsbigstroker]

does changing tunes affect fuel pressure. here is what happened, I installed fuel pressure gage was running spartans max economy tune, fuel pressure read about 65 psi, unhooked the fass pump and the pressure dropped to o at times when I would get on it, when I was running the fass pump pressure never dropped below 55 psi. Went home changed tunes to the spartans agg street and fuel pressure never went above 20 psi. I cannot understand this. thinking about going back to the looney tune. please help me understand this. Brad.

[dadsbigstroker]

I installed the auto meter gage hooked up to my billet fuel filter cap. only thing I can think of is when I was changing tunes I messed up my gage by the key being on with engine not running. When I did change tunes I pulled the fuse on the fass pump so it would not run I then reistalled fuse drove down the road and back and pressure never went above 20 psi.

[dadsbigstroker]

who ever came up with the idea to hook up a fuel pressure gage to a updated fuel bowl cap, does not work. cannot hook up a gage to that it does not work, so anyone trying to say buy this billit fuel pressure cap and hook up a gage, got news for you it does not work. I took off cap took fuel filter out and gage shot up to 60 psi again. and I dont think my filter can clog up within 10 mins. Brad.

[npccpartsman]

There is a port in the secondary fuel filter housing that requires the use of an adapter hose that's probably a better place to get a fuel pressure reading. I'm not sure how the billet cap is made, but it's possible you had an air bubble in the top of the cap and you weren't getting a proper reading there OR the filter was causing a restriction or blockage to the gauge??? Changing tunes will change fuel requirements of the engine depending on the tune, but don't blame the tune for your pressure only getting to 20psi. At idle you should have 55psi or better, depending on how the pump regulator is set. At WOT you will see some pressure drop, but that's normal.