91 Lumina z34 Regulator or Not? Help please

[comet240]

hi i posted before but i been away and couldnt test, umm i was idling my car no problems till i took it for a test drive them i idled side of road and car shut down, and i got stuck had to tow my car home

was doing testing at home, i get spark and stuff, but wont fire only way it fires

if i take out the fuel pump relay and the fuse, and i crank it over several times it will finnally fire after being flooded, but if i run car without pump running and i put fuse back in car shuts down, if i leave fuse in an no relay the car wont fire, but it will fire when the fuse is out and relay when i primied the lines and press the fuel pressure button on the rail the gas shoots high i take it its too much pressure sitting?

also its pumping so much fuel in cylinders it comes out in the muffler or the leak i have in the caylatic pours out gas,

so my question is is it the Fuel Pressure Regulator or is it the MAP sensor that pulls the regulator or is it totally something else?

[richtazz]

It sounds like you have some leaking injectors. The FPR only holds the fuel pressure at the rail, it has nothing to do with it leaking in the cylinders. Check the vacuum hose to it for fuel just in case, but I dont think that little vacuum line could allow enough raw fuel into the intake to cause what you are describing.

[comet240]

ok without taking plenium off how do i test which injector is leaking?

is there an easy way to test it?

i tried sucking on the hose that goes to regulator but its tight and i and dont hear anything


so how u test a fuel regulator also?

and how can i test fuel injectors in car but if i have to take out rail how can i test each one with a battery charger well i mean if i hook one up what em i looking for etc

[richtazz]

the only "test" for a regulator is to check fuel pressure key on/engine off, then with the car running. The fuel pressure should be 41-44 psi KO/EO, and should drop 3-7 psi while running at idle. Disconnect the vacuum while it's running, and the reading should return to close to KO/EO readings.

There is no easy way to check which injector(s) are the problem other than to pull the plugs (no easy job either on a 3.4 DOHC) and see which ones are most fuel flooded.

[comet240]

ok ill go try that

also i dunno if this helps i pulled all 3 front sparkplugs out and cranked over and they all shoot gas out alot, is that possible all injectors are leaking

or is the the fuel regulator?

well i gonna go try the pressure regular with the fuel gauge and ill let u know

[comet240]

ok i tried just KE/EO and goes to like 50psi then drops to 0 i turn engine over and it goes to liek 41 but when i stop and let the pump catch up or when it stops i mean it drops from 41 to 0

i tried testing with fuse and relay out for pump and no presure but i cant put fuse or relay back in or shuts engine off


but if i turn key on and it goes to 40ish and i turn key off it holds but drops slowly


so what do u think?

[richtazz]

Since it holds better when the key is off, I would say it's an injector issue, not FPR issue. If the FPR were bad, it wouldn't hold pressure at all.

[comet240]

oh ic but it does go down hmm so ill try it but my oleman got me a regulator from wreckers for 50 bucks so who knows

why is it holding slowly when key is off then when its on and it goes right to 0?

[comet240]

so since i really cant tell what cylinder is filling up more of fuel

if i take rail out and plug a battery charger to the inejctors what em i looking for for leaking injector?

[comet240]

ok i took off the rail but i come to a situation
the back 3 clyinders in the injector port holes have like a pink rubber and the front 3 dont have any, are they suposed to be there cuz ther 3 are diterioated but all 6 injectors have there black rubber ring i was trying to poke out the pink but its kinda hard


also i looking at rail but i still have like 30psi but i dont see any injector leaking i gonna prime pump by turning key on and having the rail plugged in to see what injector is leaking i think that might work

without turning over engine

but about rings do i need them

[comet240]

ugh this is sooo frustrating i tried what i said i take the rail out but leave it all plugged in to see whats spraying , u think any spray no none spray and after i turn key on and leave it after doing it several times key on and off it holds 40 pounds even with key on it doesnt go to 7 or 0

its really pissing me off even turning over a short couple tiems doesnt do shit i guess it has to be grounded but even with a piece of wire i used didnt do shit and my oldman got me a fuel rail off a 3.4 grand prix or am it was and u think it would fit no its formed slightly at the regulator its wider and cant fit in i gonna try to bend it but come on why is this 3.4 engine so bad lol

[comet240]

richtazz will this stump u i dunno

went to wreckers got a complete rail off of a z34 standard version
put the rail in my car thats regulator and the 6 injectors came with it

now i assemble it all and start car runs good but its running at 50PSI is that good?

now i shut it off and start it again it wouldnt start gave me problems but now its idling but now its at 55 to 60 psi idling now is that good or bad? not it running a little rough,

so whats wrong now? i suck on the vacume hose for regulator and pressure goes down a bit so i guess thats working, i also changed the map sensor but maybe i need to change ti back to orginal i had? or what else could be affecting this now

im gonna let it run an hour to see if there is any change but any suggesitions now?