z34 goes straight to 3 grand(rpm)

[SofaKingWeToddDid]

i personally dont call it retarded power (im used to well over 300) but yeah it gets alot more power over 4k. sometimes a little lower, like 3.5k, depending on how its runnin i guess... lol well for me.

iwas told not to buy one of these motors unless i LOVE working on cars. i thought, hey i like working on my car.... this could be good!!
well lets just say ive learned the difference between love and lust. i have some engine complete pics if you wanna take a look, and im still waiting for Dave from Hayes Performance to get back to me so i can shoot his motor. have you guys seen it?? i get a boner just looking at it.

[walterdude]

A good way to check FPR is a pressure test. The guage screws onto the Schraeder(sp?), looks like a tire valve stem, valve behind the power steering pump. Here's the numbers:

"According to Haynes you're looking for 40-47 PSI,,,, when you start it it should drop by 3-10 PSI. Those are a good indicator of the pump's condition. Of course what you're looking for is if the pressure holds."

An Autoparts store will rent/lend the pressure tester...
Still sounds like a LIM gasket,,, they ARE known to go... Or something that should be easy to find, broken/cracked UIM??? LIM???
Good luck,,
Tom..
EDIT: The older LQ1s had the vac line for the FPR running to the MAP sensor. You can pull the line there and look/smell for gas. As a note: bad FPRs have been known to have gas travel through this line and fill the intake with raw gas....

[SofaKingWeToddDid]

this could tell you lots of problems, low fuel pressure isnt strictly because of the FPR, it could be because of a few things, now if its high....

i prefer the vacuum test on the FPR itself, that way you are only testing one component. not a series.

[Joseph Upson]

If you haven't found the problem yet it might be the throttle position sensor. It's a long shot but when I got one wet on a TPI motor the immediate problem was a very high idle with an intermittent engine light and occasional bucking while driving. I imagine the ignition module could advance the timing enough to raise idle a good bit to if it's malfunctioning. Just a few things I experienced with OBD I systems, not sure if yours would produce the same symptoms under those circumstances.

[roho94Z]

i'll have to wait and see. tore her down to the lim got the gasket out and could not find anything that would raise questions about its integrity. needed to replace the valve cover seals anyhow, they were leaking oil down into the spark plug access holes. cant believe i paid the local GM guys to replace them a few years back. for an hours work takedown, i could have saved 1400 bucks. bunch o' thieves. if this doesn't do it i'll start trading out sensors. stayed glued to your seats folks.

[pocket-rocket]

You most likely wouldn't be able to see where the LIM gaskets were leaking if they were the cause. I couldn't see anywhere on mine that looked like they were bad many moons ago when I did them on the 91, so it made me skeptical. Sure enough when the moment of truth rolled around and I fired it up, it made its way back down to an 850 rpm idle.

[SofaKingWeToddDid]

lol is this thing still revvin high? well let me know what the problem is when you figure it out. im curious.

[roho94Z]

okay, changed everything. lim, uim, still revvin' high. very DISAPPOINTED! i'll start with the tps and go from there. bank acct's low so i need to get this right.

[pocket-rocket]

You spray your vac lines down with carb cleaner? I wouldn't doubt if there is a leak in one of the larger ones letting unmetered air in behind the TB somewhere.

[bbeck]

did you ever figure this out?

[RedZMonte]

I know this is an old post but....

If you unhook the throttle cable's from the throttle body then start it, does it idle normally? could be a sticky throttle cable.... either way its something simple to try.

S

[roho94Z]

Ben @ admin wanted me to do a final on this. turns out it was the IAC. i purchased a new one and installed it but the problem remained. so i rigged a plug and inserted into the open IAC port then cranked er up. guess what, it idled normal. Bad IAC, returned said POS and got a NEW new one. problem solved. kinda irritating to tear apart the UIM and LIM for the second time in two years,( i can do it less than an hour now, whoopee!) only to find its the part right in front of your face.

[pocket-rocket]

Ouch. Good deal on finding the problem though

[Jogasz28]

FWIW,
My Z34 had bad intake manifold gaskets, idle would change from idle to 3K, stay there, or slowly drop back to idle.
Never threw a Code/SES light. OBDI.