ok, the setup. 95 lt1 90 camaro rs. the car starts idles perfect too. however i took i have noticed the fuelpump whines really really loud and bad <walpro intank pump 255 lph>, usually its about 60 seconds after it starts before the squeeling gets unbarrable. it changes sound and gets worse, after it sets 15 minutes its quiet again. i took the car out today. car has no tags so i havent road tested it much. first run up the street it ran good. then i turned around and tried again. when i hit WOT the car downshifted, lost all its power and spuddered and backfired a time or two the pump was louder then the stereo. the pump is new however, but i dont know whats causing this. do you think the pump could be the culpret? ideas? advice? ill try to put a fuel pressure gauge on it tomarrow.
thanks guys

 

I'm no deity, but I can tell you that getting that fuel pressure reading under the test conditions might go a long way toward identifying the problem.

 

Id run some MMO in the gas. I do that every so often.
It will lube the whole fuel system n smell nice too.

I think it helps keep the pump alive longer. Most are just plastic parts cooled with gas so not to get to warm and be a problem. But a splash of lube ever so often has to help.

 

Definitely need a fuel pressure reading.
What's MMO? I get that it's some sort of fuel system lube. But MMO acronym?

 

New fuel pump or not, if its squeeling that bad then something is definately wrong and getting replaced. I agree with the others, sound like fuel pressure to me (or lack thereof).

 

fuel pressure reading...... idel 35 psi hard acceleration ruffly 35-38. was night time and couldnt see it if i drove it around, so with it in the garage i reved it to 4500 a few times and help it there. also i changed the fuel filter, still squeels but not as bad i dont think, and when i was reving it up it seemed to quiet down some. i dunno! ill see if i can take it out sunday if i get back in time to see how its acts.Also thought i read somewhere walbro intank pumps where a bit noisy

 

MMO = Marvel Mystery Oil. I just use 2-cycle oil every fall before storage.

 

Never heard of putting oil in the gas before. What quantity is useful?

Sounds like your fuel pressure is on the low side. You can test it by applying power to the fuel pump test connector. Make sure your fuel pressure tester is attached to the rail. Slowly squeeze the fuel return line with pliers. Watch your pressure. Should rise. DO NOT allow the pressure to exceed 60psi. The stock regulators weren't designed to handle more than that. When I tested mine I just brought it to 55psi. Since I wasn't seeing those pressures in my car, and I then knew the pump could push those pressures, my pump was deemed good.

Crap. You have an LT1. This may not apply.

 

Hey,

I have a 98 GTP and I used to have a Walbro pump in it. It started whining really loud also. Eventually it went out and left me on the side of the road. The pump noise went from a loud high-pitch whine to a loud low-pitch growl. If you have ever heard a cat growl out of anger, it kinda sounded like that (I have a cat. And a wife. Im in trouble!!! LOL!).

I would replace it PRONTO! I didnt have that pump in the car for a whole year!

And since it was my daily driver, I didnt have a need to put Marvel Mystery Oil in the tank. It does work when youre storing a car for a long time.

 

started messing with the car again last night, i unplugged the vacuum line from the regulator. pressure shot up to around 50. i plugged the vacuum line back in. pump wasnt making a sound sounded almost like factory, reved it a few times pressure looked good and no noise from pump. turned engine off let it set a hour came back. same deal. working perfecto no noise or anything

 

If it ain't broke...

 

Yeah... My Walbro did the same thing. Thirty minutes later, it started growling again and the car started acting stupid again.

 

yea car started acting stupid again i looked at the fuel pressure gauge and when i would rev the engine up via the throttle body the psi would drop to almost 0 and well the engine would bod and almost die. so i guess its either the regulator or pump. even with the fuel regulator vacuum hose removed and reving it would still go to 5 or 0 psi. which one is it!? possible voltage drop going to pump? im lost:P

 

Sounds like the pump to me...