2002 Boxster S problem- HELP!

[BayAreaKid]

There is nothing mechanically wrong with my Boxster S. However when I try to accelerate, the car just automatically decelerates when it reaches around 25 mph. I believe it is the MAF sensor, but I am not really sure. I can never reach freeway speeds because of this limiting problem. It also does not go above around 3000rpm. Any help would be appreciated. I see a lot of people are viewing my topic, however are not responding. please help

[1schoir]

There is nothing mechanically wrong with my Boxster S. However when I try to accelerate, the car just automatically decelerates when it reaches around 25 mph. I believe it is the MAF sensor, but I am not really sure. I can never reach freeway speeds because of this limiting problem. It also does not go above around 3000rpm. Any help would be appreciated. I see a lot of people are viewing my topic, however are not responding. please help

Kid:

Aside from a possibly bad/fouled MAF sensor, have you looked into the possibility that your fuel filter might be clogged.

A common symptom of a clogged fuel filter is that it will allow the engine to reach certain RPM's and then the rush of fuel through the restricted filter cuts off and the engine won't make more RPM's.

For the MAF, do a search here and you will find two procedures to try to narrow down or eliminate as a possible source of your problem. One involves cleaning the MAF, the other involves driving the car with the MAF disconnected.

Also, are you getting any CEL codes?

Regards, Maurice.

[Brad Roberts]

+1

Fuel filter or fuel pump headed south. Hook it up to a PSTII or PIWIS and perform the volume test :)

I'd start with the fuel filter, cheaper and easier to do. Just south of you in Mountain View is Heyer Performance, he will drop you off and pick you up from the train station if you want to take the car to him. He is right near Google off of 101 and Rengstorff (650) 962-0930 (Tony)

B

[Stefan]

If you think the problem is the MAF then try unplugging the MAF and see if the problem goes away. I doubt that the problem is the MAF. I would start by removing the air filter and shaking it out since that is the easiest to do. If it hasn't been replaced in a while and you have an extra lying around then I would replace it.

[BayAreaKid]

Thank you all for the suggestions. I will try them all and see what happens. Brad: I will definitely check that out, because I live in Mt. View. If anyone else has advice, I would appreciate it.

[Brad Roberts]

Tony is on Rengstorff and has been since the early 80's. He was a wrench for the original Garretson Enterprises race teams that ran Leman and beat the factory 935's :)

Tell Tony "Brad" sent me. He will look the car over for you for free.

b

Edited February 24, 2009 by Brad Roberts