Jfrahm

Some sections of the exhaust are double walled and the inner wall can sag and block exhaust flow.

http://www.944online.com/images/prod...Q/PA160062.JPG

TheDice951

Where in the exhaust would this most lilly occur?

Jfrahm

Crossover and up pipe area. Between the header and turbo.

Paulyy

Did you get around checking the tps? is it sending a 5v signal out on WOT?

TheDice951

i checked the tps... i followed the instuctions on clarks garage. the first step was to check the DME harness at "idle" and mine read 1.7 and OL as soon as i touched the gas. then it said to use pin 22 and 23 on the KLR harness? i didnt see a diagram and the KLR harness isnt marked with numbers so i checked it from the TPS it self and found a combo that read 470 at "idle" and went up steady with throttle movement so i am assuming it works right.

i will have to wait until the weekend to do anything with the exhaust though since i have to work and its my daily driver.....

thanks guys!!!

schip43

The elbow for the turbo to the down pipe is double walled and can collapse internally.
http://www.broadfootracing.com/944%20Exhaust.htm
3" 321 Stainless Down Pipe

Picture is half way down. This what they are talking about, stock has an inner wall. Not saying this is your problem. And there have been "issue's" actually getting parts from these guy's!

TheDice951

if this is my issue then i will just make one up myself to replace it... thanks for the link though...

TheDice951

so, just an observation and i dont know if it has anything to do with my issue but....

i have a narrow band air/fuel gauge(i know you cant really use it for anything buit it was in there when i bought the car) i dont have the interior in so it was just sitting on the floorboard until yesteteday. i just sit it up and watched it when i was driving.... shows normal until it starts popping on spirited driving... it drops to lean, very lean and it shouldnt? i dont know what would cause that, the FPR is good, the damper seems ok(not leaking out of the vacuum port) so either the injectors, filter or pump?

what do you guys think?

schip43

I have both and yeah, you can't really tune with a NB but they have a value! And that value is just what your seeing!
It's telling you stop trying to boost till you get this fixed! Or your next thread will be:How do I change a headgasket!

Black51

Are you running stock injectors? If so, that, or a clogged fuel filter would most likely be the culprit of fuel starvation. I think the stock fuel pump can pump more fuel than the stock injectors can handle.

+1 on the headgasket thread. Turn down the boost for now! At least until you get the fuel issue sorted.

333pg333

So do you have a wideband and if so what reads are you getting?

TheDice951

1st, i cant turn the boost down... im running off the wastegate spring as it is. 2nd, i have 55lb injectors and im running 12lbs.

i am not running a wideband but i wish i was...

i think i will change the fuel filter since that is the cheaper part of the system... thanks for your help and i will let you know what happens

TheDice951

so.... still having the issue.....

took entire exhasut off and have no issues with it

replaced the TPS and that did nothing

replaced the cap and rotor... nothing

fuel filter, replaced and nothing...

im getting tired of this.... im thinking about taking it to european performance in raliegh NC and see what they can do....

TurboTommy

Could be something up with one or more injectors.
All it takes is one bad injector or loose connection; you'll lose one cylinder, so it will have no power and O2 sensor will show lean.
But then you said you checked your spark plugs.

schip43

Well I'm gonna throw out the least costly throw dollars at fix, that might work because I have tried and tested everything else suggestion. Replace all the ic coupler hoses, especially the TB to hard pipe hose!

I know you tested it but they just get old and oil soaked and work there way lose. I swore might was tight but I broke down and replaced it and that fixed it.

The car would boost till about 3 to 4K then it woulkd hit a wall and I remember a sound like rushing water.

Couldn't hurt.