mudbuddha

Try turning/clocking your MAF unit a little bit...check ground and dme/klr units to make sure nothing is loose. good luck.

TheDice951

No change, and all is well with computers....

I'm getting a headache!!!

Scott H

You did a vacuum test but did you do a pressure test? Things can leak under boost that wont under vacuum.

schip43

Yeah it sounds like a boost leak to me also. I had problems with the TB to hard pipe coupler, it looked ok but it would pop off under boost, at 4000 rpm and it sounded like a water fall. I'd replace that one at the minimum and see if that helps

Black51

Although I agree with the majority with a possible boost leak, the rough idling seems like a different problem. I would maybe check the TPS next. Possibly ISV also.

What year is the car? If '86, do you have a venturi delete?

Jfrahm

Collapsed exhaust pipe, cat or blocked muffler?

TheDice951

its not a boost leak, i have check, multiple times and replaced couplers and boost pipes as well.

it is an 86 and yes it has the delete

no cat, all exhaust is piping is good and the muffler is a straight through so its not blocked...

i will be doing the TPS check tomorrow

mudbuddha

Hmmm...install MBC unit again and see if it makes a difference? Also check, or install a different DV?

Black51

Hmm, adding fuel to a fire never seemed to put it out before.... but maybe just this time it might...

TheDice951

the diverter valve is a forge unit and seems to be working properly. i will be checking the TPS today and screwing with some other stuff too... we will see what the results are.

thank you guys for helping me figure this out... its getting frustrating....

PorscheDoc

Did you check all the bolts on the wastegate mount flange? I've seen those back out and cause the same issue.

fast951

- How did you check the pre-turbo exhaust? Did you verify that there is no obstruction as in collapsed inner wall?

- When you press the accelerator too fast, where is the "popping" coming from? Exhaust/ Intake?

- Which injectors are you using?

Jfrahm

FOD to the turbo then maybe.

Jfrahm

Yes, if it sounds funny it has to be something that changes the sound. A collapsed up pipe makes a lot of sense and fits the problem profile but supposedly this has been checked? Maybe the collapse was not noted in the inspection.

TheDice951

I pulled the entire exhaust off and checked what I could... I was checking for cracks and signs of leaks. I didn't notice any collapsed tubes...

The popping sounds like it's coming from the exhaust....?