z34 goes straight to 3 grand(rpm)

[SofaKingWeToddDid]

starter fluid didn't locate leak. sprayed it about anywhere i could get into. still taching 3g, smokin and its fuel and not oil. what could cause it to dump so much fuel, and not throw a code?

take your UIM off and make sure that vacuum line for the FPR isnt pinched off... seriously, mine did the EXACT same thing. bouncing off the rev limiter, right?? and didnt you have yours off just before this prob happened to do gaskets? or did i read that wrong?

[roho94Z]

not black smoke, grayish blue haze, does not smell like oil. okay whats the fpr and uim my manual really doesn't tell me where half this stuff is. just a picture and guesstimate the location

[robertisaar]

FPR=Fuel Pressure Regulator.
UIM=Upper Intake Manifold.

obviously look around the fuel rails for the FPR(no pic, i don't have a 3.4)
and the UIM is the pretty self explanitory...

and oil usually burns a light blue color
fuel is black
coolant is white

doesn't have to smell like oil to be oil. the cat usually absorbs most of the smell/smoke too, so thats something to consider...

[SofaKingWeToddDid]

my vacuum line was squished under the upper intake, thats the huge gray thing behind the black 24V DOHC plastic cover, and the rear valve cover. it wasnt cut, just squished. once i moved it, the problem was fixed. the fuel pressure regulator is the thing on the transmission side of the engines fuel rail ( the thing all the injectors are connected to) and its a round thinggy, i dunno, the only vacuum line that attaches to the fuel rail anyhow... so its a tough one to miss when youre looking for it, easy to squish if youre not.
trust me, if its a stupid mistake a guy could make while fixing his car, ive made it.

[SofaKingWeToddDid]

best i have is a picture with the upper intake off, and the fuel rail is out, but its looking at the side of the car where the pressure regulator is.

there is also a metal vacuum line that is bolted to the fuel rail (not technically part of it) that is for the transmission this one is obviously a little tougher to squish. lol

[robertisaar]

i'm amazed that the vacuum line would cause this much of an issue. about all it does is drop about 10psi from the injectors at/around idle and increases pressure as the MAP goes up...

[roho94Z]

aint i stoopid, wrote that in my early post. double bourbon straight up. 02 was changed when the uim and lim were changed. but the cat. is original, and it rattles. could it be creating this mess. the fpr is under the uim so if the line is pinched i'll have to tear 'er down

[SofaKingWeToddDid]

it takes me about 20 mins to take off the UIM if i have to dig through my little tool box to find everything, if all of the tools are laid out, 10 mins, no prob!! lol mind you its just a pain in the ass looking for a 10 and 13mm socket in a mess of others.
recently i purchased a few sets of colour coded sockets on holders, so maybe i can get my times even faster. lol

[SofaKingWeToddDid]

wow these pictures make my motor look dirty, but i just wanted to post them, if you have it this far apart, its a good idea to check the oil seals on the PCV line, the plate its connected to, and the oil pump drive seal

[robertisaar]

i almost forgot how big the ports were on LQ1s....

a rattling cat won't cause this, but it does need taken care of.

[SofaKingWeToddDid]

heh and i can fix the oil pump drive seal and not touch either intake manifold, aside from taking the air cleaner off the end of the upper

[pocket-rocket]

The bigger problem with the line being pinched isn't the fact that the FPR isn't regulating pressure, it's that the plastic line creates a huge vacuum leak since the UIM and LIM can't make a good seal trying to be mated together with the vac line in the way and there is air being ingested that the TB isn't controlling. If you think those LIM ports are big, you should see the ones on the 96/7 manifolds.

[robertisaar]

ahh, now it makes sense. but shouldn't starting fluid anywhere near it have made it rev even faster?

EDIT: JESUS TAP-DANCING CHRIST! its no wonder why the motor can't make any torque under 3000RPM... but what a healthy pull it gives from 4K and onward...

[pocket-rocket]

Isn't it a thing of beauty? And yeah, starting fluid would have made a huge change in the way the engine was running, and I would imagine if it were a quiet engine, you would hear the leak as well.

[SofaKingWeToddDid]

depends on how much gasket maker a guy uses i guess...