HELP! Weird driveability problem

[releese78]

Hmmm, sounds like a good idea. I'll change the MAF. $3-400 is definately worth the risk of getting plowed by another car!

[pk2]

Sounds kinda like fuel starvation. In that it craps after 15 minuets (about warmed up) it's no longer running rich and maybe regular lean mode is just to lean. I had this problem exactly in a BMW. Mine was always the fuel filter .

Given you've covered that base, you might take look at the fuel pump. Tests usually involve flow and pressure (2 tests).

Good luck, PK

[pbanders]

I'm with PK, first thing I thought when I read this was fuel starvation. I'd check pressure and supply, fuel filter, fuel pump, fuel pump control, and if the Boxster has one, the tank sock (mesh filter in the bottom of the tank).

[2000SoCalBoxsterS]

Have the CATs ever been replaced? They must be fired by 102K miles.

[releese78]

Dont think the cats have ever been changed, but I doubt its them since its only intermittent. The problem happens within the first 15 minutes of driving, after it warms up, it seems fine. The fuel filter has been changed recently, this didnt help. I also changed the plugs, and they old ones looked very good, nice brownish color, no oil burning or over-lean seeming condition. I'm not sure about the MAF or O2's, I havent changed them. I have cleaned the MAF though.

[idheaton]

Yes, it did feel like fuel starvation. Like when you run out of gas and the engine dies out only to catch when the fuel sloshes back to be picked up.

I had changed my fuel filter @ a 60k service so it wasn't that and also tried numerous things (as stated in my previous post) before changing my MAF. The reason I did that last was I never once has a CEL so thought, 'It's not the MAF'. Ended up changing it as a last resort and it fixed my issues.

This might not be the cause of your problems, just do not rule it out.


Releese,

if you do decide to get a new MAF, you can find them online for 200-300 as opposed to 300-400. You just have to do a little searching.

http://www.********************************************************************************************/search/?N=11567+1698+4294967268+9359

http://www.drivewire.com/products/porsche-boxster/air-flow-meter/133/

http://www.aboveallmotorwerks.com/product.aspx?year=1998&make=40&model=986&maketext=Porsche&modeltext=Boxster&CategoryText=Fuel%2fAir+Intake+System&Category=F2***&SubCategoryText=&SubCategory=***

Quite a few online discount autoparts places that have it cheaper do not list it as a Mass Air Flow Sensor but mix up the name calling it a Mass Air Meter, Air Mass Meter, Air Mass Sensor...the word jumbles goes on.... ... just make sure you order the correct one.

[Lil bastard]

Again, like I said, too much room for speculation here and that's all it is - speculation.

Others may have had similar symptoms which were corrected by changing 'X', but that doesn't mean yours is the same problem. Though it may be (emphasis on may )

Lots of different things can manifest themselves as similar symptoms. For instance, as mentioned, it may well be the cats. What you describe is exactly how a failing cat might work - takes longer to warm up, until then, the DME selects all sorts of screwy maps resulting in poor drivability. Could be the secondary air system which prevents the cats from warming up properly, or timely - same effect.

My point is, get the car on a PIWIS or PST2 and find out what's really going on before throwing mucho dinero at a problem which may not cure your car's ills.