Boxster drivability issues

[kieferskustoms]

97 boxster 5spd 127,xxxmiles. When i first got this car it had an issue where it has a dead spot in the rpm range when at wot. I replaced the maf sensor with an aftermarket one and it worked perfectly for 3 days with no bogging at all. Then wouldnt start. It would start if i unplugged the maf. Sent the maf back and got another aftermarket one. Same thing. Lasted 3 days then no start. Would start when outside temp was above 50 degrees or so but not if colder. Replaced the maf again. This time with a new bosch sensor. Now starts but has the mid rpm range bogging. Tried unhooking the battery to reset the ecu. Didnt seem to help. Do i need a porsche scanner to fix this problem? Does it need reset correctly or need a software update? Any ideas? Im an ase tech but dont normally work on porsche so im kinda lost on this one

[White987S]

Do you have any fault codes? Is all your maintenance up to date?? Things like spark plugs and coil packs???

Edited October 23, 2012 by White987S

[kieferskustoms]

Maintenance is all good. Just did air filter, fuel filter, plugs, etc. no codes. It used to throw codes for bank 1 and 2 lean but i havent seen those codes in quite a while.

[White987S]

And your coil pack and wires are A-OK? What about the health (clogged) of your fuel injectors??

[kieferskustoms]

None of that is the issue. Basically if i put an aftermarket maf sensor on my car it runs perfect until i gets below 50 degrees then wont start. With a bosch sensor it starts up all the time but has a couple dead spots at wot. This problem is related to the maf for sure. I just cant figure out if i keep getting messed up sensors or there is a specific relearn procedure that i dont know about.

[mikefocke]

Is it the MAF or a sensor that is sending a bad signal to the ECU?

Is there a relearn after battery disconnect? Yes...pretty long and complicated involving multiple runs at multiple throttle points and other variables. Until then the ECU uses some presets.

Are we sure that the Bosch MAF is the correct one for the model year you have? 0.280.217.007 sometimes sold as B3130-70627? Same as the original "bad one"? Any sense that the ECU has ever been flashed?

[kieferskustoms]

Well as far as i can tell its the maf but i wont rule out something else. Yes thats the part number i have. Same as the original. I have no idea if it has been reflashed. I dont have a porsche specific scanner to find out.

[kieferskustoms]

Just checked fuel pressure and fuel volume. Pressure is low at only 35psi. Volume is exactly what it is supposed to be. Im thinking i need a fuel regulator