boost = NO torque

[Heyst]

Yes I've searched and I found GREAT stickies about maintenance and tracking down problems, but if I don't entirely know everything about this car its almost like reading Japanese.. so here it goes

I accelerate like normal, maybe a little harder (I DO baby this car) and when the psi goes up, the acceleration deteriorates excessively. Its like an anti-turbo. hah. If I hold it and let try to let the car pick up it'll jolt as if I am flicking an on-off switch for boost.

Like a couple threads down I too can hear my a/m BOV (at least I think its coming from the bov) releasing air, and then when I let off it lets out the usual pressure sound.


I wiggled some hoses and everything seems tight. I read I should tighten the clamp on the intake, but is it the one holding the filter on?

also, will cleaning the MAF maybe fix this problem?

I diiiiiddd searrchhh.

[rak123]

maybe the BOV isnt tight enough and is leaking? prob a boost leak somewhere

[Heyst]

so go to town tightening it onto the flange?

if its a boost leak and I don't have a propane torch, what spray can I use to detect the leak?

[Skym]

Air leak after turbo makes a whistling sound. If BOV is leaking, so is the J pipe (intake pipe that's shaped like a J) that goes over the top of the engine.

[BrianV8]

a torch will only detect a vaccuume leak not boost

[Heyst]

well, is it a hole in the j-pipe its self? or the cuplers?

I know I know, go get my hands dirty. I'll report with progress.

[BrianV8]

What rpm does the pull seem to fall off? Because i know with the factory tune + factory turbo the top end is really gutless, all mid range power

[Heyst]

It's during mid range for sure.
Its a serious noticeable drop in acceleration, almost completely no 'go' at all, and if I come to a stop sign and down shift, but coast in neutral to the sign a good bit, then the car will stall. If I give it some gas then it will come back up to normal RPM idle.

the idle fluctuates too when I am coming to a stop (under no load).

It's just odd, boost goes up, RPM's go up, but the car just doesn't want to take off at all (already moving without boost). If I ease off it then the car will jolt and TRY to take off like it should.

I tightened all clamps. could this be a leak on the MAF side? the ribbed hose that connects to it? or could it just be the MAF needs a cleaning. I inspected it tonight and its a little dirty but not seriously dirty.

[Skym]

That's what an airleak on the J pipe does and feels like. What I mean is, if the airleak is under the BOV or on the 1 inch or so rubber recirculation joiner hose off BOV, could lose vacuum, boost and cause idle or returning to idle problems.

On my car it was the throttle body rubber joiner leaking. It had gone hard, due to engine bay heat. I just replaced with a multiple ply silicon joiner hose that supposedly resist's heat better.

Airleak near MAF makes engine stutter when idling or accelerating and doesn't lose boost. If you accelerate enough, sometimes the stuttering goes away. But if airleak is big enough, sometimes it doesn't.

The rubber intake pipe after MAF can crack between the ribs and create an airleak. Sometimes it's the intake hose clamp infront of turbo that needs tightening.

[deliberate32]

You say it jolts eh? Well when my car had MAF issues, this sounds like a similar problem that I had, it wouldn't boost any more at 2500-3000 rpms...


Try taking your MAF apart, and resoldering the connections in the maf housing, and clean the sensor up with electrical cleaner.

[WildCard_]

youve been pm'd

[Skym]

Engine can run without MAF, but like you have found, is limited rev wise. I gather the limp mode on stock ECU rev limits engine.

[Heyst]

I am being told from the place I bought it that a clamp isn't tight, or I have a vacuum leak?

maybe I should look for vacuum diagrams.

EDIT: Well I bought all new clamps, cleaned my maf, and did a K&N filter recharge (I know useless in my problem, but why not)


I found that the clamp on the turbo MAF side was loose. I hope that is the problem. I am waiting to make sure the maf is completely dry to take'er for a burn.


thanks everyone for your help so far

[Heyst]

post whore = me... clearly.

anyhow, like wild said I am going to go with a new fuel pump. thats the issue.

thanks!

gtr pump, or walboro?

[WildCard_]

Curious, did you test your fuel delivery system first?