S14 SR breaks up under load

[Former_240_s14]

Hey guys quick question:

Intermitently my motor begins to break up and stumble under acceleration. It idles perfect and when its not under load its fine. I have checked all the hoses and clamps that would be vacumed related and they all seem fine. I also doubled check my exhaust to make sure its all buttoned down as well.

I am thinking its maybe that my fuel pump is begining to bite the dust.......

Any thoughts?

Thanks,

Rubin

[snake240]

if your running the stock pump then id say thats the culprit. i would def upgrade and get a an adjustable fpr as well. im running the nismo and just got an inline gauge from summit.

[Former_240_s14]

I am not running the stock pump. I was told it had a walboro unit when I bought the car but its been in there for a while. I have checked the following other items and cleared them of the issue:

Coils
Boost Controller
Visible Vacum Lines
Exhaust leaks

It's making me wonder if the pump is just dying.... Its very very intermitent (sp?). The car runs like a scalded dog for a week then runs rought for another.

Thanks for the input

Rubin

[USMCgetsome]

i had that same issue and it was a slowly failing fuel pump (walbro) It was friggin terrible to diagnose because it idled very well but would seem to pause going through 5-7800 rpm. Strange occurance but i check and cleaned every damn thing u could think of. Tps, maf, throttle body, fuel pressure reg, fuel lines, fuel filter, spark plugs, coil packs.

[Blown240sx]

Id also check your spark plug gap. You could be blowing out spark.

[Former_240_s14]

Thanks for the input. Since my last post I have done the following....

replaced fuel filter
replaced plugs

Still same issue. My buddy who works for a performance shop is going to check it out friday. He did the install and thinks it could be the maf.....I still think there is a small issue of a failing pump but he is definately the expert.

Keep your fingers crossed.

Rubin

[PyR0NiAk]

Bad MAF should cause the same issue whether the car is under load or not..