Possible fuel pump starting to fail??

[Unstock240]

Well I've been trying to find the problem on my 89 hatch for quite some time. I swapped my kade for another kade and it too has similar symptoms. The car hesitates until about 3k, but now the overall powerband has slowed. I replaced my only code34 (knock sensor) still no go.

I think maybe fuel pump because of this: Two times during the summer it made a high pitched loud prime unlike usual. Normally I cant hear anything. I have swapped tons of things. fpr, injectors tune up and many things including ecu. Also changing the timing +-5 seems to do nothing and I uplugged the tps or whatever.

Also I have always had to give it gas for about 20 sec or it will die. The only reason I think this isnt related is because I have no emissions stuff. No egr or emissions stuff. My idle is perfectly stable after about 20 sec of giving it some gas.

Anyone have any idea what could be?? I will be going tomorrow to get an inline pressure tester to see if the fuel press is good or not.

[rsmithdrift]

Go search all posts by me. I had the SAME EXACT PROBLEM for the past 2years. I did the same thing you did. Replaced everything under the hood. But the problem kept getting worse untill finally it wouldn't even run. I would idle but if you hit the gas it would just cut out and make popping noises from under the hood.

It was the gd fuel pump the whole time... It kept getting worse and worse untill it wouldn't supply enough fuel for movement.

Replaced it with a Walbro 255lph and now my car 0-60's in 6 seconds.

All those things I replaced gave the car alot of power once it had enough fuel to do something with.

It's only 90 bucks and you need to replace it anyways no matter what so if it wasn't the problem you upgraded ahead of schedule, and if it WAS the problem (almost gaurantee it is) then you saved yourself a f*** ton of money trying to find the problem under the hood.

[SrS13]

Have you tried checking your fuel pressure while the problem is occurring? It's the only way to be absolutely certain that your fuel pump is failing. I also had a similar problem just recently that I thought was fuel related and it turned out to be my ignition wires.

[Unstock240]

Well I tested my fuel pressure and its way too high. I got something like 60psi primed, and 75 something idling. Could My vacuum to my fpr be bad or what?

[Unstock240]

Well I took a bicycle pump to all 3 of my fpr's and made up my own test. I pumped air into each through the fuel inlet sealed. All of them held shut until about 45psi, so I would say my fpr is good then? I pulled the vaccuum as well and felt vacuum. Not sure how much though.

Apparently if the return has kinks or clogs anywhere the pressure could climb? I'm thinking maybe my fuel pump sock could be clogged? I have no idea what else causes this. I dont belive my pump is bad with that much pressure either.

[Unstock240]

Anyone helphelp? It is running worse everyday haha, and im stumped.

[rsmithdrift]

Ive never heard of one making too much preassure... with a stock pump.. crazy.

But that would make you run rich wich would make the car hesitate if it's flooding. But it would be blowing black smoke out the tail pipe and idling up/down looping backfiring and everything else too if it was THAT rich for it cause a problem.

You should have 34psi at idle/decel and 44 psi under accel.

Maybe run a new return line then??

[Unstock240]

I guess I'll unhook the return into a bucket and check it for about 30 seconds. If pressure drops then my return is clogged or something. I tried another gauge with the same results too. It does seem to miss for the first of starting, and it pops and crackles more than I think it should was well.
Modified by Unstock240 at 11:03 AM 2/16/2010