Do I need a new fuel pump?

[Big Rizza]

Hey everyone,

Im going to take my car to a qualified mechanic for a full diagnosis, but i thought id ask you guys first so I have an idea of what cost i have coming my way.

Ive just imported an R32 GTS-T 4 door, and when I use about 3/4 throttle at above about 4500-5000 rpm, there is a big power loss and the exhaust makes the same rumbling that happens when the engine is on the overrun after lifting off at mid-high rpm. The power loss seems to come it at the same time as the (factory) boost guage reaches its maximum. It seems to happen most when the air is cold. On a hot day i could drive very hard without any such problems. I havent used full throttle in these conditions so i dont know whether it clears up with more throttle (aftraid of killing car).

The other symptom is that the fuel pump is very noisy, and can be heard over the 3.5 inch HKS exhaust up to about 1/3 throttle. Im not sure whether its a noisy aftermarket fuel pump, or whether the current fuel pump is dying.

Do these symptoms sound like a faulty fuel pump causing fuel starvation? I was thinking the fuel may become more viscous or something in the cold which is why the symptoms arrise... or the fuel pump may be less efficient when cold... Anyways, Im not very good mechanically, so I'd appreciate the feedback.

If it is the fuel pump, what's the bill coming my way? Is it worth upgrading to a larger fuel pump now if I want to increase boost some time in the future? WOuld a used RB26DETT fuel pump be best?

Thanks in advance for any replies!

[joh21m]

for your 4500 - 5000rpm problem:

check your spark plugs, sounds like u need to gap them to 0.8mm, if its only in the cold maybe your car is boosting that little bit extra and its missfiring....

i think you might have a big ass fuel pump but im not sure, is it a whining noise all the time or only wen cold???

[Big Rizza]

cheers joh21m, i'll get the spark plugs checked out. And the fuel pump makes the whining noise all the time.

[Zahos]

Changing your spark plugs will help reduce the effects of this problem, but this problem usually stems from your coil packs.

Check out this thread , and also this thread, as the issue is covered a plenty.

Also search for more threads of coil packs, hessitation, misfire as there are about 10^9 of them.....

[maxforce]

pull out the fuel pump ya self and check if its got a ject pump in it. see if the fuel tank is clean or there is rust in it. also replace the fuel filter most of the import cars has been sittin for so long that is time to replace them. do a full service and if ya keen pull out the injectors and get them reco. just take one step at a time and you be right. any problem pm me. i used to be a mechanic at BMT

[joh21m]

if its whining all the time u might be lucky and have a big pump, if it was whining on and off or only in the cold then i'd be worried, but do wat maxforce says, one step at at time it'll work out...go to a mechanic you know who works on imports and ask him to look at your pump, if you cant do this yourself, and he'd b able to tell you straight away...

let us know how it goes.

Joh

[Bazelinez]

I'd say its hitting the factory boost cut if its boosting to the end of the factory guage. Mine onlly gets to around the half way mark.... Its a fuel cut so it could sound like a dodgy pump.

Cold air will make the problem more obvious as it will boost higher in the cold as the air is denser.

Check this first with someone in the know as your fuel pump sounds like an aftermarket job.