Had my 996 turbo at track Saturday for a DE event-1st track visit . Car ran great for 5 sessions-very strong compared to my old S/C M coupe. But during last session it started to have idle surge and when I oitted it surged up/down 400-900 rpm and eventually stalled down but CEL didn't come on . On drive home CEL came on and i couldn't accelerate very well . about every 20 kms I would have to pull off and recycle the key . when home I checked the turbo hoses and looked for any vaccum hoses off-all looked ok .Codes stored were P1101(innput variable charge measurement) , P1249(boost pressure deviation below minimun), and P1508(function monitoring torque comp.) . when i unplugged the MASS it idled fine . I ordered a new MASS and installed it today and cleared stored codes . Idle was still surging so not sure what's next? Does it require a drive cycle with the new MAFS ? Should I disconnect the battery?-I have Durametric cable.
TT has a Vivid 650 upgrade kit with Softronic tune done in 2008 by precious owner.
what do you think?
Thanks
Wayne

 

All ways reboot. ... make sure a hose did not come off. Double check. Recheck the hoses coming right off the turbos.

 

I'd see if the throttle adaptation makes a difference, test for boost leaks. Then see if the code comes back

I had a 1508 but coupled with some other codes. Turned out the tb was hanging open.

 

HI,Most common,,check intercooler hoses coming off of turbo and rubber coupler from Y-Pipe to TB..
Good Luck

 

sounds like a vacuum leak... dvs... etc....

pressure test the car...

 

Leak for sure check all ur hoses zip tie all vacuum hoses you can find and tighten all ur clamps if still cant find pressure test

 

Dont waste time. Just do a boost leak test.

 

He says as if everyone has a compressor and *****in home depot homemade boost leak tester lol

It might be more comprehensive but anyone ( me? ) can check to see if an if IC hose has popped. But I sure can't boost leak test myself.

So I say checking the obvious ones by looking at the ic hoses or tugging on the y-pipe is hardly a waste of time

 

...agreed..

 

checked with Marski@ 911 tuning and he will have boost leak kit available next week(excellent response to my question and great asset to forum to have him and his company contributing.
I'm going to pull the wheels and fender liners to inspect for obvious leaks today
(coffee first and then out to garage!!). Hope for the best because I only have a couple of months before its storage time and start on list to get ready for spring.
BTW I did install a new MAFS ( old one was 4 yrs old) but didn't help.
Thanks all for your input and I'll update later.
Wayne

 

^^ congrats on finding the boost leak yourself by checking the intercooler hose. proving once again. look first/tug first. boost leak test... only as needed lol

 

Went back at car today and started over- removed wheels and fender liners to get better look at turbo hoses . Found right boost hose off the intercoler--success!! removed the hose cleaned the inside and the nipple on the intercoler with brake clean . Re-installed it and tightened all clamps
Road tested and all is good .
Proves that sometimes I have to stand back and think longer !! Can't rush repairs.
Attached are photos of boost hose off; completed repair and after road test .
Thanks for the input from all of you .
Have a great day
Wayne

 

Because 5hp 10hp compressor is super expensive. And even making a tester or buying one is hard. LOL

Btw grats finding the leak.

 

it won't save you time if you pressure test before looking at the ic hose LOL.

so lets see the one you made! pics?

 

Hmm..I think someone said to check that first in an above post..
Great,,glad you solved the problem..