00Jay

Wanted to get some input on what I've been experiencing over the past week with my 07 Turbo, 49K miles.

During WOT (but not every time), I experience a lag/loss of performance above 4000 rpm. Feels like a huge drop in HP. Wanted to additionally note that the turbo pressure doesn't drop. I've driven a few times since and had the engine shut off when coming to a stop at a stop light. The car is now parked until I can find a shop to look at it.

After searching the forum, it sounds like the problem could be related to:

- Bad or dirty MAF
- Cracked or damaged coil pack
- Spark plugs (Probably not the issue since I've recently had mine replaced and gapped for tune)

Hoping to find a decent shop here in Phoenix/Scottsdale in the next few days...if anyone has a recommendation, please feel free to reply or PM me.

COBB Tuning

Maybe a boost leak? I would check to make sure that you don't have a boost leak somewhere.

I would also check to make sure that the VTG actuators have full motion.

You are in Phoenix it could be something as simple as a bad tank of gas mixed with insane heat.

Hope that helps some good luck!

-Mitch

aa909

Heat will definitely give you this feeling of "loss power". Does this usually happen on very hot days ?

00Jay

That was my thought at first as well. First time it happened was on a 111 degree F day. But, I've driven the car at night a couple of times and have experienced a couple of lagging WOT pulls too.

Kevin

Here is a quick, diagnostic procedure. Fill the tank with 50/50 mix of race gas. If the car pull like it previously did and strong>>your tuning most likely has too much timing. Timing retard is taking place. You can also monitor your exhaust pipes. When the engine goes into stress, for component/engine protection>your fueling Lambda drops causing black tailpipes.

sharkster

Check and see if the vacuum line came off th FPR on the passenger side you can usually feel/see it.... Happens a lot Zip tie the bugger on...

Steamboat

Hoping to find a decent shop here in Phoenix/Scottsdale in the next few days...if anyone has a recommendation, please feel free to reply or PM me

Evolution Motorsports in Tempe.

John@Fabspeed

Sounds like it could be a vacuum leak. Stalling at lights would be consistent with that, but having an intermittent vacuum leak would be... strange. Did you check the computer to see if there were and stored or pending codes?

00Jay

Will have to check that out...

another note...after starting up my car yesterday and taking it to red line one more time, I think my clutch is starting to slip...won't be able to try that until I get the clutch worked on.

Thx for suggestion, will check out tonight.

Thx for suggestion!

I'm shopping for an OBD reader right now as I type this.

EVOMS

We're located in Tempe near the 101/202 interchange, and would be more than happy to take a look at the car. We're intimately familiar with the 997 Turbo, whether it's stock, tuned, or has 1500whp+, and do diagnostics/repairs and service in addition to performance and ECU tuning in-house.

Give me a call if you'd like to set something up, 480-317-9911.

Thanks,
Sam

aa909

Interesting insight, but what exactly do you mean by "black tailpipes"? When my car was 100% stock the inside of my tailpipes had plenty of black soot. and now with a tune they are about the same to slightly more sooty (is that a word LOL!) on the inside. So does "black tailpipes" mean the entire exterior of the pipes is also black?

thanks for clarifying
Art

Kevin

Run your finger inside the tips. You will see black soot on your fingers (more than normal). You can also see black soot on your bumper cover. Periodically one should examine the tips to keep a baseline. Datalogging your engine performance and logging Lambda and knock retard is a good thing.

aa909

Yeah no soot on the bumper. I guess what I was getting at is that our engines with the stock setup produce a lot of soot as it is so if a tune was producing more it would end up all over the bumper as you describe.

eurotom

If you drive it hard enough your tips will turn white!!!

Kevin

You can be running a lean map> will turn the tips white (not counting race gas). With 91 octane we want to run a little more rich vs a 93 octane map.

You also can be running good one day, and have a fuel pump issue (run lean) High knock retard with heavy fueling=soot

Put another way, if you watch your tips, you will quickly know when something isn't correct.