1/4 Tank=Loss of Power?

[rudee023]

I have noticed a slight but noticeable loss of power when my gas tank gets down to around 1/4 tank. It is slight but you can definately tell the difference when you fill up. The only thing I can think of that might be the cause is when I installed my Walbro, the rubber gasket that seals the access panel to the pump was pretty wasted. I get a little bit of gas smell from the rear of the car after running and my filler cap doesn't "hiss" when I open it. Could the tank not being pressurized be the cause of my problem?

[Hijacker]

it's a common thing in 240s. Every 240 I've driven has had power loss issues after the tank gets under a 1/4 tank

[240SXer]

I have noticed a slight but noticeable loss of power when my gas tank gets down to around 1/4 tank. It is slight but you can definately tell the difference when you fill up. The only thing I can think of that might be the cause is when I installed my Walbro, the rubber gasket that seals the access panel to the pump was pretty wasted. I get a little bit of gas smell from the rear of the car after running and my filler cap doesn't "hiss" when I open it. Could the tank not being pressurized be the cause of my problem?

Ya, i've noticed this when I got my SR and walbro. Mine is when it gets to E. It used to go well below E and be fine, but now it starts running ****ty at the E line. So it's like I really have a 15 gallon tank and not a 17.. who knows... It could be the position of the pickup on your walbro.

[SoCalS14]

Funny you should mention this, cuz Howard over at Phase 2 told me not to let the car go below 1/4 tank with a Walboro...I guess its either bad for the car, or bad for the pump...

[mynismo]

with my last car the sil80 i ALWAYS kept a maximum of 1/4 tank for weight reduction issues, using a walbro, and i've never had a problem. with this one i normally fillup the tank when gas is cheap, but when its less than 1/4 tank i never have a problem, even when the light lights up.

i would say its your fuel pump, but it looks like some of you guys have the same problems, so that can't be. weird....

maybe you need a fuel pressure regulator. fuel pressure could be dropping with less gas in the tank.

[jaboc03]

I have the exact same thing happening to my car since the walbro was installed. It hits a 1/4 of a tank and the fuel light comes on and it runs kind of choppy.

[rudee023]

Has anyone found out why this is? What if I got an adjustable FPR and raised the pressure a bit? What is the most I could safely raise it with stock injectors @ 13psi of boost?

[Hijacker]

the main reason you don't want to run below a 1/4 of a tank too often is moisture. It all depends on the humidity of the area you live in. For instance, my area is notorious for leaving moisture in a gas tank if you leave it too low for too long.