fuel system questions

BALZY_GT · Jan 19, 2012

I'm looking for advice about the fuel system on my supercharged 94 GT. I have had the car spit and sputter after a quick quarter mile full throttle run. I have also blown the maxi fuse in the engine compartment that controls the fuel pump after some agressive driving. (I'm using a walbro 255 in tank pump hooked up to the factory wiring harness with 42lb lightning injectors and stock fuel rails.)
I'm wondering if i should put on the aeromotive 30amp fuel pump wiring kit (part # a16301)
I have also been told that I should install a high flow fuel rail kit. What do you guys think I should do? If I should put on the fuel rail kit, what do I need to make it fit the 94-95 GT? All of the kits say they only fit the 87-93 mustangs.

toyman · Jan 19, 2012

Are you sure it's a fuel and not a spark issue. Are you running a spark enhancer? The Walbro 255 lph (GSS340) and stock fuel rails should be good to about 500 hp.Other than a short the fuse shouldn't blow because of your driving. Also check the volts to the fuel pump. Voltage less than 12v or bad grounds will affect pump output.

BALZY_GT · Jan 20, 2012

Yes, I'm using a MSD 6A ignition and blaster coil.

mikey94gt · Jan 20, 2012

Check the grounds on the fuel pump and wiring back there for loose connections/corrosion, that will usually trip a fuse. It could be a bad pump too.

modo · Jan 22, 2012

how old is the pump? i would swap the pump out and also there should be a in-line pusher pump. 255 really isn't sufficient by itself. replace the fuel filter as well

the factory wiring is fine for your need and also the factory rails / lines are good to well over 600 rwhp so i wouldn't spend money on something you don't need

toyman · Jan 22, 2012

On rereading the original post I noticed that there is no mention of a tune. To the OP, how was the car tuned and was this condition present at that time? I think without some history possible fixes are just wild guesses.

Musturd · Jan 22, 2012

This ^ msd 6a is garbage

BALZY_GT · Jan 22, 2012

The fuel pump was new when the blower was installed 2 years ago. The car does have a custom SCT tune, but I'm not using a pusher pump. Do you think that a pusher pump would solve my fuel issues?

Which size maxi fuse should be running the fuel system? Is anyone running a larger fuse?

Musturd · Jan 23, 2012

Do you run a wide band ? That's a good way to see if it's a fuel problem

BALZY_GT · Jan 23, 2012

no I don't

modo · Jan 23, 2012

BALZY_GT said:
The fuel pump was new when the blower was installed 2 years ago. The car does have a custom SCT tune, but I'm not using a pusher pump. Do you think that a pusher pump would solve my fuel issues?

Which size maxi fuse should be running the fuel system? Is anyone running a larger fuse?

if your blowing the stock fuse then you have a amperage draw issue... replacing it with a larger fuse will just cause you more issues (potential fire).
all the s-trim kits came with a pusher pump on return style systems. it should be there honestly as it helps keep the fuel pressure up. fuel pressure gauge dropping off is the best way to know for sure and as long as the factory wiring has not been hacked up (something tapped into the fp circuit) i would say you have a fp issue due to the symptoms with the fuse.

if you have access to a dyno and a clamp meter you can take amperage readings on the wiring while the car is running to see what is going on. its hard to diagnos while driving and if you are having a fuel delivery issue you don't want to hurt the motor etc etc

if it was my car and funds were tight i would borrow a clamp meter and get readings on prime, and start the car. let the car heat up to temp and see what the amp readings look like. you should be able to get #s off of walbros site on what kind of draw the pump should be at. a clogged fuel filter will put more load on a pump but i doubt it would be enough to kill the fuse unless the sock in the tank is blocking the pickup etc. if it is the pump there are newer pumps that will not require the pusher style but that is your call.

BALZY_GT · Feb 18, 2012

do you guys think i should go with an inline vortech t-rex pump, or should i put on a kenne bell boost a pump kit?

forcefedhatch · Feb 18, 2012

Replace the 255, don't add anything else.. If it keeps blowing fuses check your grounds..255 is plenty.. We have pulled near 550 from a 351 on stock rails numerous times with no issues at all...

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