Hwyranger

Hello everyone,
Drove my 96 993tt from Phoenix, AZ to So. Cal. yesterday. Car is completely stock with 32k miles. I noticed the car would stutter/hesitate under accleration. Also, the car seemed laggy. I could only see 0.4BAR. On one occasion, I really mashed the throttle and saw 0.8 BAR, but not until 5k RPM. Are my turbos bad? The gentleman that sold me the car said the stock BOV's might be bad. Any input is appreciated.
Thanks,
Enrique

Jean

Enrique

Has the IC been removed recently?

Are you hearing any unusual "whistle" while under boost that might suggest boost leak? The symptoms are quite typical of a leak. Could be a loose IC hose or some other leak from the TB/intercooler side or the turbo side.

chris walrod

Where in SoCal are you now? I could take a look at it for ya if your near the OC.

Hwyranger

I'm in Murrieta. Just north of Temecula, south of Riverside/Corona. I've these billet BOVs that aren't installed. Anybody ever have problems with the stock BOVs?

Thanks again,
Enrique

ScottMellor

Hopefully you have diverter valves and not Blow Off Valves. The 993tt is a closed loop system.
It does sound like a leak at this point from your description. Te stock diverter valves really don't give much trouble on these cars.

Hwyranger

You're right, it does re-circulate. I called Walter's Porsche in Riverside and made an appointment. I'll update this board with whatever they tell me. Thanks.
Enrique

erva71

sounds to me like your MAF is bad and you might be running in limp mode. The stuttering is typical when your MAF goes. Also the high 5k rpm/ 0.8bar scenario is also typical of being in limp mode.

Hwyranger

Per Walter's porsche, looks like my car just needed its 30k service. (I was told it was done prior to me purchasing it.) Apparently the plugs were really bad and the engine was misfiring in several cylinders. This probably put the car in limp mode as erva71 suggested, hence no boost. Billet aluminum diverter valves are also being fitted. Car won't be ready until Thursday most likely, I'll post what the final word is. Thanks for the help everyone.
Enrique

Hwyranger

Ok, picked up the car yesterday and the car definately runs better, however I'm still only seeing 0.5BAR on the digital boost meter. I was in third gear at about 2500RPMs and floored it, revs rose to 5k-5.5k and I only saw 0.5BAR. The car does not stutter anymore, or at least it hasn't done it yet. The car does not smoke. I removed the intercooler prior to taking the car to Walter's and I noticed lots of oil on the right side intake charge pipe. Is my right turbo dead? Am I only getting boost out of one turbo? I'm taking the car back in obviously but any feedback is greatly appreciated. Thank you.
Enrique

ca993twin

Enrique,

Was a PPI performed on this car prior to purchase? Checking the intercooler hoses and watching for full boost should be standard inspection points. In any event, if you have lots of oil in the intercooler, you may have a blown seal in that turbo unit. It should, however, still be making boost, so your .5 bar (limp mode) would indicate some other issue. If you indeed need new turbo units, consider sending them up to Kevin (UMW) for a rebuild. A pair of stock rebuilds is around $1500. He can also crank in some more HP in varying degrees... talk to him for ideas.

Is your "check engine light" warning bulb connected? Often times, an unscrupulous seller will simply disconnect the bulb to sell a car with a CEL issue. You may be able to find an error code stored in your ECU that will decsribe a problem related to the low boost. Or... it could simply be a leak.

Sorry that you are experiencing problems with a car that should be pure ecstacy! Good luck.

Hwyranger

Ca993twin,
Thank you for the response. I bought the car used w/30,020mi. from a Porsche dealer in Az. They told me a meticulous inspection was done and no problems were found. No check engine lights. No smoke. However, when I drove the car from AZ to CA, it stuttered on acceleration. Walter's Porsche in Riverside found the error codes in the computer, they said it was multiple misfires in several cylinders due to faulty plugs. The Porsche dealer in AZ paid for the replacement of the plugs and I paid for a full 30k service with a leak down, all cylinders came in within 8-11%. Stock diverter valves were swapped out with billet aluminum ones.
I got out of Supras to get into Porsches and I can't put a finger on my porsche boost issue. Apparently Walter's couldn't either, they had the car for a week.
Thanks for the info nonetheless.
Enrique

erva71

have your MAF sensor replaced, I was having same issues as you but since replacing the MAF its running just fine. Full boost .8 everytime. 8%-11% seems a tad high for your mileage btw.

chris walrod

I have to agree -- upwards of 11% leakdown is quite high. Then again, if the car was babied, there is a good change it will retest much better after some good 'ole Italian tuneups.

erva71

exactly that, Italian tune ups are the way to go with these 993s. Dump a can of SeaFoam into the tank and drive it like you stole it for a good 100miles.

Hwyranger

Anybody know where I can find a MAF? Walter's Porsche says there are none in U.S. and have to order from Germany. 3 week wait, minimum. Does anyone out here stock MAFs? Thanks.