FUEL issue, 5.3l walbro255. QUESTIONS
09-22-2011, 11:11 PM
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FUEL issue, 5.3l walbro255. QUESTIONS I have a 2000 5.3l installed into a 79 chevy 3/4 4x4..
the 2000 has a FPR built into the fuel rail, vacuum controlled.
Feeding the system is a walbro 255, with an-6 fuel line. and 3/8 hard line.
ive been having lots of issues with running way rich, thinking it was intake gaskets, MAF, IAC... etc
but today i got a chance to hook up a fuel pressure gauge, turned my key and the gauge spiked to 110 psi, slowly dropped to 30 psi and stopped. okay... then i started it, and it was running with fuel pressue at 110, (way rich and smoking)
and it blew of my fuel rail FPR again...
what else can i do to control this fuel issue? do i need another regulator or should the truck one be fine?
here is some live data i also have
any input or help would be great
the 2000 has a FPR built into the fuel rail, vacuum controlled.
Feeding the system is a walbro 255, with an-6 fuel line. and 3/8 hard line.
ive been having lots of issues with running way rich, thinking it was intake gaskets, MAF, IAC... etc
but today i got a chance to hook up a fuel pressure gauge, turned my key and the gauge spiked to 110 psi, slowly dropped to 30 psi and stopped. okay... then i started it, and it was running with fuel pressue at 110, (way rich and smoking)
and it blew of my fuel rail FPR again...
what else can i do to control this fuel issue? do i need another regulator or should the truck one be fine?
here is some live data i also have
any input or help would be great
Last edited by Dillon93dillon; 10-05-2011 at 10:31 PM.
10-01-2011, 02:13 AM
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fixed the return line issue, was restricted on the fuel sending unit. wasnt designed to have very much fuel coming through.
but now that ive been driving it, its not what i anticipated. of course im pushing 38" tires, but my buddy has a 79 with a sbc 350 and on 37" tires and i feel that he would walk away from me easily.
are there any live data things to look at during driving that may cause this "doggy" issue.
reminds me of a sbc to far retarded on timing, or being heavily loaded.
Now i drove my truck for a couple days, it ran fine (still doggy), smelled something almost like a burning smell, as i was pulling in the driveway, just figured it was from how i was driving.
Next day it starts, runs for about two min, and starts miss firing, shut it down, tried it again, and one min later starts doing it again. (seems to be as soon as the 02 sensors would be activating i think)
im wondering if the fuel pressure is to low, its at about 45-50 psi at IDLE. Full throttle gets to about 53 to 56. before i fixed my return line issue, the pump was running 110 psi, so im hoping i didnt screw it up
also today when i moved it, i noticed that if i full throttle (this is ever since its been running basically) that its very doggy, but i quarter throttled to get moving and going, and it wants to take off and go like i expected this motor to be like.
Trying to figure out what kinda problems i could have going on here, and input is appreciatedthanks
today, my brother brought over his AUTOTAP and we couldnt find any issues at all, which is good, but its not good because it was acting up with me day before...
Hooked fuel pressure gauge up, about 44 to 45 at idle, with the fpr vacuum line unhooked(full fuel flow) was about 54 psi. it has good flow also.
when i drive it, it seems VERY DOGGY, feels like a 350 way to far ignition retarted.
Bleeding the brakes ATM so i couldnt hook up pressue gauge and drive it, but when i put it to the floor, it doesnt seem to take off very fast at all. i know its got more, because my stock 350 had more power.
if anyone can help point me in the right direction, or any input would be great
but now that ive been driving it, its not what i anticipated. of course im pushing 38" tires, but my buddy has a 79 with a sbc 350 and on 37" tires and i feel that he would walk away from me easily.
are there any live data things to look at during driving that may cause this "doggy" issue.
reminds me of a sbc to far retarded on timing, or being heavily loaded.
Now i drove my truck for a couple days, it ran fine (still doggy), smelled something almost like a burning smell, as i was pulling in the driveway, just figured it was from how i was driving.
Next day it starts, runs for about two min, and starts miss firing, shut it down, tried it again, and one min later starts doing it again. (seems to be as soon as the 02 sensors would be activating i think)
im wondering if the fuel pressure is to low, its at about 45-50 psi at IDLE. Full throttle gets to about 53 to 56. before i fixed my return line issue, the pump was running 110 psi, so im hoping i didnt screw it up
also today when i moved it, i noticed that if i full throttle (this is ever since its been running basically) that its very doggy, but i quarter throttled to get moving and going, and it wants to take off and go like i expected this motor to be like.
Trying to figure out what kinda problems i could have going on here, and input is appreciatedthanks
today, my brother brought over his AUTOTAP and we couldnt find any issues at all, which is good, but its not good because it was acting up with me day before...
Hooked fuel pressure gauge up, about 44 to 45 at idle, with the fpr vacuum line unhooked(full fuel flow) was about 54 psi. it has good flow also.
when i drive it, it seems VERY DOGGY, feels like a 350 way to far ignition retarted.
Bleeding the brakes ATM so i couldnt hook up pressue gauge and drive it, but when i put it to the floor, it doesnt seem to take off very fast at all. i know its got more, because my stock 350 had more power.
if anyone can help point me in the right direction, or any input would be great
