Hi everyone !
My name is Julien, I'm a new member and in first of all I apologize for my english (I'm a noob with car and english language .
I live in San Francisco and the last month I bought this boxster:
http://sanfrancisco.dollon.net/post/...a-Porsche.aspx

1998, 29 000 miles !
So, I made the 30 000 miles revisions with oil changer and some stuff (breaks...).
After 1000 miles, a the check engine was UP, I read the code and I saw a problem with the MAF.
I changed the MAF and the light never appear again.

But since one week, when I push hard sometimes, I really can feel a loss of power.
Each time I push over 5000 rpm, the car loss a LOT of power, I have to stop to push, wait somes secondes before continue to push again.

Any other time, when I go slowly on the road, the thing goes fine and no light check engine.

I was wondering if bad spark plugs could lead to that or if any other trouble could be the culprit
bad fuel filter, ... ?
clogged injectors?
faulty fuel pump?

I really don't know. Porsche technician don't know, he says "I tested your car and I feel that all is fine, no fault code I can t do anything"...

If someone has an idea, I'm not an expert so each idea I will ask to Porsche to try to solve the problem.

Thank you !

 

If you haven't maybe you should do a major service on it. It seems like it would be due about now. Also, it wouldn't hurt to do injector cleaning. I remember I had to do that when I lost power all of the sudden going uphill on my other car.

 

Congrats on the car! That is almost exactly the car I had a poster of that hung above my desk during school and training. I looked up at that and daydreamed from '97 to '05 when I bought my first sports car, a 2001 Boxster (silver, 21,xxx miles).

I hope you love it as much as I've loved mine.

 

The tech drove the car and I assume you told him outlined the steps or the way you drove the car to get the engine's behavior to appear and he was unsuccessful in producing the behavior?

If he can't reproduce the behavior and there's no CEL and no other symptoms...

The MAF was replaced?

Who did this?

IIRC earlier model year Boxsters that require a new MAF must also have a DME upgrade applied. I do not recall the details and this means I do not know if the new MAF will work but just not work well with the older DME firmware (which if this is the case could be what's going on with your car) or if the new MAF simply will not work at all until the DME firmware is upgraded.

Also, there's the question of the replacement MAF being well, I do not know how to put this, but of sufficient quality. There have been reports of people buying MAFs online and saving some money but having less than the results expected. IOWs, the online MAFs while they fit/connect are not the same as the genuine article.

One trick to see if the MAF plays a role is to disconnect at the connector the MAF and drive the car and see if the symptom/behavior appears. If it does then the MAF is not the problem.

A fall off in power with no CEL is hard to diagnose. The plugs may be questionable. Even though the car is a low miles car the plugs could have suffered from hard (or too easy) running, the wrong gas (lower octane or cheap gas), or the plugs could have been replaced and the wrong plugs used.

The fuel filter may have become partially clogged. As long as you do not drive the car in a way that its fuel needs are too high the fuel filter can pass sufficient fuel. But push the engine and the filter can't pass enough fuel and the engine loses power. Generally though the engine recovers very quickly as the throttle is closes and the fuel needs drop, then reproduces the behavior when one gets on the throttle again hard.

Or the fuel pump is weak or grows weak from heat and its output drops off until the behavior appears and the easier driving allows the pump to recover.

Or the engine may just need a couple of bottles of Techron run through the gas tank as per directions to clean teh fuel system, remove deposits in the injectors, the intake valves, and combustion chamber surfaces.

Unless you want to fund a throw parts at the car until a new part replaces the bad part you need to have some professional diagnosis done. While this can cost you, an hour's labor (maybe a bit more, but nail this down before going ahead) it can save you hundreds of dollars in unnecessary parts cost and maybe a thousand (or more) dollars in unnecessary labor cost to replace the unnecessary parts.

Sincerely,

Macster.

 

Try Hi Tec Auto in San Rafael -- Devin is the best...

 

Welcome and hope it will be an easy fix for you.

 

Let us know how you make out.

 

Hello GUys
So finally after I changed the MAF and the fuel pomp and filter, the problem appear again (((
One time per week, I have a loss of power (it could be in second speed or five, no matter).
I have to stop the car and after 1 minute all work fine again...
My porsche technician don't know what is the problem..