I replaced the fuel pump this weekend due to a 7psi reading at idle and no sustained fuel pressure when the pump was off (would drop to 0Psi)

i replace the pump, 13PSI at prime AND idle, yet the car seems to still exhibit at least two of the symptoms it had previously, hard start, and high idle..

i was hoping that the car was going lean due to the failing pump which might cause the high idle and that the hard start was simply due to lack of fuel, but now im not so sure...

shouldnt a low pressure contribute to some sort of issue though?

i did not have a lot of time to test it so im thinking that there may still be air in the lines. what do you guys think? ill go home and drive it tonight, i had to cut off the sway bar endlinks with a saw due to damage so is it safe to do a little test drive with no rear sway?

also im having an issue getting what i htink is the Stabilizer bar reattached, the part that "zigzags" down by the rear end. the bar that goes across the back parallel to the rear end seems to be a half inch short and wont fit up with the bracket... not sure why.. possibly bent frame? anyways. let me know what u guys think, whats a way to test the car? i sure hope i didnt replace the fuel pump for no reason...

im beginning to think that maybe the old pump was fine and my actron pressure gauge wasnt screwed into the inline T adapter correctly, the schrader valve, maybe it wasnt pushing the pin in correctly causing a resistant opening.... cause when i got the pump back in, i jumpered the relay wires to start the pump and check the pressure and i would get 0 psi, until i unscrewed and rescrewed in the pressure gauge fitting, then i got 13psi...

just a thought. i sure hope not

 

iac? just a thought
do you have any mods that could cause an open vac. line? that could cause the high idle

 

Did you replace the filter when you changed pumps?If you have alot of miles then you did yourself a favor by replacing that old pump.I did that last christmas. Make sure that the throttle position senor is ok also.Just check your connection.

 

Ok i did a test drive, the car seems to have like twice the horsepower as it did, so definately happy about that, however, high idle, somewhat hard to start (though it seems better now)..


there is a loud hsising during start up that receeds with the idle speed. i am thinking that it could be a leak in the intake manifold gasket,

i have no modifications except for a n open element air cleaner which i dont always use (sometimes use the stocker.. for the iac sensor)

the TPS isnt adjustable, unless you mean just generally ok.

um im going to check out the MAP sensor since it deals with vac, maybe replacing that will do some good... it definately seems to be a vac leak, and probably a big one, seeing as it idles from 1500-2000 RPM

and i know its not just the tach being off, the engine sounds like its working harder and when im braking to stop the car works really hard against me.. when i let off the brakes it like half of a jerk forward and it start moving at like 10 mph immediately.. so definately idling high...

duno what else to check but vac leaks/map sensor stuff...

i have used up 6 cans of carb cleaner looking for vac leaks, found one in the TBI gasket, replaced that, replaced all but a few of the vac hoses (the two that go into the firewall *hard plastic ones*, and the one that goes to the fuel evap canister..)

i have a feeling that the fuel evap canaster is probably full or something, any way to check this?

also, i seem to be leaking some fluids, but i moved it to a different spot in the garage so i can monitor this better. i think its tranny fluid, possibly some engine oil too...

what do u guys think? im going to replace the MAP if its relatively cheap and go from there, if that doesnt help, i guess ill have to remove the intake manifold and replace that gasket, is that very hard?

thanks guys!

 

BTW i actually cleaned my IAC, but broke it in half when reinstalling it (guess i over tightened) so its got a brand new on in there, do they come lubed up from the factory? cause i just stuck it in, maybe i should lube it up?

also, yes i replaced the fuel filter...

OH BTW guys!, i had a crack where the fillter tube meets the gas tank, at the base of the filler tube around the base, so i covered it with some gas tank repair putty stuff... any idea if this crack can cause a loss of pressure? or is there a check valve inside of the pump that keeps the pressure at what it is supposed to be at?

my pressure is at 13 at idle and prime, but when the pump stops working, the pressure decreases slowly, down to about 2-4 PSI... is this normal for a TBI car? thanks

 

Did you reset the ECM? You may have to drive it for a little while so it can calibrate again

 

A vacuum gauge can be your best friend sometimes.

 

i will try resetting the ECM tonight, i dont think thats the issue though... the car is running great now, it seems that everything fuel and spark related is in good order...however.. there is still that highpicthed hiss, and symptoms of a vac leak...

i think im going to point the finger at theMAP sensor or maybe an old intake manifold gasket..

my TBI gasket and all other gaskkets ive looke dat so far are burnt looking (black) and crusty falling apart.. even the fuel injector meter gasket was in bad condiiton... the high idle, still a little slow to start, and the hissing noise.. it all seems to point at vac leak... what do you guys think about the MAP sensor, is there any way to test it out before i replace it with some 50 dollar part that might not fix my problem? i really dont feel like spending any more on parts that dont make a difference.. i can justify my current purchases (such as the tune up and TBI rebuild since they are things that should be done every so often and ptobably werent ever done) but i cant buy a part without knowing for sure it needs replacing thanks guys!

 

hmmm
vac gauge that sounds like a very good idea... although its like the fuel pressure gauge in a way... its a 40-50 dollar part that will simply tell me if there is a problem... i wonder if there is a cheap way to MAKE one. im going to google this!!!