996 Goes Flat

[Sly74]

HI All

I have a 98 R 996 Carrera 2 tip, it has a flat spot at approx 5000 revs, sometimes clears after 5k revs, sometimes feel

flat all the way to 6.5k

Has anyone heard of this before? Can anyone suggest a cure?

Regards

Sly

[RFM]

Hi

Do you have already changed the air mass meter?

[Sly74]

Hi

Do you have already changed the air mass meter?

I havent had the air mass meter changed, is it an expensive item, can it be check, or should I just replace?

[RFM]

What is expensive? I have no idea what the price is in the U.K. On the continent it cost about Euro 140.00.

Yes it can be checked with a PIWIS tester, menu - DME - actual values. A fault code is not always necessarily, a disturbing in the airflow results in a problem. This is not really a DIY job. Replace the air mass meter if necessarily.

Regards

[Sly74]

What is expensive? I have no idea what the price is in the U.K. On the continent it cost about Euro 140.00.

Yes it can be checked with a PIWIS tester, menu - DME - actual values. A fault code is not always necessarily, a disturbing in the airflow results in a problem. This is not really a DIY job. Replace the air mass meter if necessarily.

Regards

Is there anything else I should check? or is it only likely to be the air mass meter?

Regards

[Loren]

IMHO... not unless someone put in the wrong spark plugs.

[Sly74]

IMHO... not unless someone put in the wrong spark plugs.

Forgive me what is IMHO? I am still trying to learn the abbreviations in this forum.

Regards

[Loren]

In My Humble Opinion

[Sly74]

In My Humble Opinion

Thanks

[sheldonv8]

Sly74, hi, i have exactly the same problem on my 98 C2.....It just start the other day after i had disconnected the battery to sort out my malfunctioning alarm......Its like hitting a switch, you get to 5000 and it still revs, sounds the same but doesn't actually pull like it used to...has disconnecting the alarm done something???

[ArneeA]

Have you guys tried cleaning the MAS and/or the Throttle body also?

Edited October 24, 2007 by ArneeA

[Danyol]

I had the same symptoms when my CAT converter started to fail (rattling from the exhaust).

[sheldonv8]

Yep, it was the MAF....i tried re-booting by removing the earth but it made no difference, cleaned out the throttle body again did nothing, so then went for a drive to get i warm. I stopped and unplugged the connection and the engine died. It started fine, idled real smooth and pulled like it never has before...all the way to 7!!

I called my local bosch parts place "Tytherleigh Vehicle Electrics" and was quoted £172 plus VAT (17.5% for the Americans) which i didn't think was too bad......Rang the Porsche Dealer and they wanted £339 plus, so guess where im going on Monday!!!!

This forum has been very helpful in sorting out this problem so thats guys

[sheldonv8]

Yep, it was the MAF....i tried re-booting by removing the earth but it made no difference, cleaned out the throttle body again did nothing, so then went for a drive to get i warm. I stopped and unplugged the connection and the engine died. It started fine, idled real smooth and pulled like it never has before...all the way to 7!!

I called my local bosch parts place "Tytherleigh Vehicle Electrics" and was quoted £172 plus VAT (17.5% for the Americans) which i didn't think was too bad......Rang the Porsche Dealer and they wanted £339 plus, so guess where im going on Monday!!!!

This forum has been very helpful in sorting out this problem so thanks guys

[Sly74]

HI All

Just to let everyone know I have had my car serviced and replaced the MAF sensor. The car goes like it should. Amazing that one sensor

could make such a difference.

Thanks to all of you that helped with this problem. A big thanks to Joe & Phil @ HP Motorsport, Hainault. These guys serviced the car for me, and made

my 911 run like a 911 should.