Car wont stay running

[CJ_Boxster]

I have a 97 Box non-S, Today when i was driving home from the x-games, i accelerated in 1st gear hard and at about 4800rpms, the car stumbled as if i let off the gas suddenly...Now i get home and take a shower and get back in my car and start it and it Starts for about 1.5 seconds before it stalls. So the Car starts and the RPMs goto about 1100rpms and then right back down to 0000rpms...


Is this typical of a faulty Feul pump or feul filter?

if it is the Filter, How and where is it installed?

If it is the Pump, How and where is it installed?

[blinkwatt]

Did the car shoot out smoke when it stumbled?

[CJ_Boxster]

Used my dads odbII scanner and came up with a code "P0102 Airflow signal / curcuit low.

which equates into a standard P0102 Mass Air Flow Sensor - Below Lower Limit that we all know and love....I got the car to start and then i erased the error codes from the system and about 11 minutes later the CEL came on and i checked the code and it was the same P0102. Well im still within my 30 day warrantee from the dealer. Guess ill inform them of the issue on monday after my LAPD test.

[CJ_Boxster]

But it does run now but just has the CEL on. When it finally started it, a loud POP came from the exhaust which is usually a calling card of a faulty MAS.

[Brucelee]

I was going to guess MAF.

[boxsterx]

I had a similar problem before and it turned out to be the MAF.

[CJ_Boxster]

Just got my car back lastnite from the dealer after they replaced the MAF. I noticed 3 key things about the drivability of the car that were different, 1...I didnt have to tap the gas between shift to match RPM's, its pretty smooth transition without having to bump the throttle now.

2, The engine stays WAY cooler now, the engine temps lower and are always touching the 8 now...Before the temp was always touching the 0.

and 3. Feul mileage, its alot better now.

I think the engine temp drop is cause the faulty MAS was sending an air temp reading of -40 degrees while it was malfuntioning so the engine would run hotter cause its thinking its freezing outside. If not, oh well the cars great now.

[MNBoxster]

Originally Posted by CJ_Boxster

...I think the engine temp drop is cause the faulty MAS was sending an air temp reading of -40 degrees while it was malfuntioning so the engine would run hotter cause its thinking its freezing outside. If not, oh well the cars great now...

Hi,

Uh... Nope. Engines don't work that way. The MAF does not signal ambient Air Temp to the ECU (DME in Porsche Parlance), it signals the Mass of Air flowing past it. Nor does the ECU regulate Engine temp in any way although it does marginally respond to it by altering Spark and Fuel to maintain a stoichiometric mixture.

The only engine temp regulating devices on the car are the Radiatyor Fan temp sensor (which switches the fans on once the coolant temp reaches 185°-190°F ) and the coolant thermostat which remains closed, closing the loop to the radiators, until the engine coolant reaches 100°F to reduce the engine warm-up time to keep the period of high emissions as short as possible and allow the car to idle well when cold.

Glad you got your issues resolved, but any reduction in temps is either a placebo effect, lower ambient air temps, tightening of the serpentine belt, bleeding or topping off the coolant, or cleaning of the radiators. Hope this helps...

Happy Motoring!... Jim'99

[CJ_Boxster]

Well I know how the cooling system works, I know the car does hair a intake air temp sensor or else i wouldnt have gotten my OBDII scanner to give me a Intake Air Temp reading...Its possible the intake manifold has a sensor for that. But i do know for sure that the OBDII scanner said Air Intake Temp: -40. And its a 7grand scanner, called Solius...if my spelling is correct.

None the less, the car runs great and I love it!