HELP! Installed T-REX...now fuel psi goes down??

Maybe you installed the pump backwards... and it's pushing the fuel back into the tank???

Hey, it is a serious answer. If you installed in backwards, it would be pushing fuel the wrong way. It could happen.

May sound dumb but ... are you positive that your fuel pressure guage is correct? Also, can you hear your T-rex running at all times? Make sure you have it hooked to a reliable power source where it can draw the amount of current that it needs.

So far there's nothing in your post that indicates a problem. That T-Rex is a pass through pump. The only time that thing is going to kick in and provide any kind noticable action is when the fuel pressure and get's so high that the intank pump can't supply the volume necessary to feed the hungry fuel rails and injectors. If you're installing this T-Rex on a fuel system that's running at near stock fuel pressures then you're wasting your time. All you'll really accomplish is a little bit of extra heating of the fuel. A regular ole intank 255 pump flows about 233 lph at 40 psi. Any guesses for the T-Rex? How about 162 lph at 40 psi. Those inline boost pumps are designed to provide additional pressure and/or volume when the rest of the fuel system gets down to or below a predetermined point. The T-Rex is pumping all the time, don't get me wrong, but it's not going to show you any measurable result unless your fuel demands exceed the output of your stock pump. And yes... in this case, your T-Rex IS providing a resriction. At normal fuel pressures, an intank 255 outflows a T-Rex and the T-Rex is just getting in the way.

Completely agree with what dagger said. You dont really need the T-rex with a 255 intank pump. If your set on running an inline pump, you need to run a bigger one.

IMPORTSMOKER said:

but my a/f gauge is still showing a solid rich reading....

Click to expand...

Unless this is hooked up to a wideband, its not giving a real reading anyway.