My car has been hesitating for about a second before power comes in ... at times it would stall when coming to a stop .. or would stall when the AC compressor comes on. It would also occassionally fire a MAF hot film fault; although, it would go away after a restart.

Durametric says no fault. I took it to the dealership, and they confirmed no fault as well.

I've been trying to figure out this issue for quite a while now and for some reason, I can't seem to get a concrete solution.

Help anyone? Thanks in advance.

 

https://www.6speedonline.com/forums/...about-diy.html

 

This could be a fuel supply problem. How recently has the fuel filter been replaced? Common problem is splitting of one of the rubber fuel lines in the tank. You might want to open the top of the fuel tank and take a look for this.

Jon

 

Done the MAF cleaning a few times... will check out the fuel lines ...

 

If you have a durametric, you can log the MAF values and look for noisy data, outliers, etc.

MAFs are funny things...they can cause serious driveability issues, yet the DME reads them as "OK". Unless a maf dies, totally, no signal, the dme doesn't really understand it is giving bad data... sometimes if they are acting up, you can unplug it- if the car smooths out, new maf time.

Kevin at UMW recommends maf replacement as regular maintenance, and I've done that with other cars as well...

A

 

It also might be the fuel pump itself. Just replaced mine because of "hesitating for about a second before power comes in ... at times it would stall when coming to a stop .. or would stall when the AC compressor comes on"
Finally its just didn't start. New pump and problems are gone. But as a precaution I also changed that fuel line, it's not so fun to soak your hands in gasoline many times, so why not to do it all when you're there.

 

I actually replaced my pump too, but I repaired the old split line and am keeping it for a spare. The new pump comes with all of the internal lines.

Jon

 

I ditched the OEM VDO pump and replaced it with a Bosch 044, it's in the slightly modified OEM sump. But I don't need the jet pump lines because of different ( C2 ) fuel tank.

 

Where's the best place to get a fuel pump? anyone has the part number?

Whats the diff between the standard OEM and Bosch 44?

 

Is your car stock? Seems MAFs really start to act up once you turn up the boost.


I'm so happy with the Hitachi MAF. Totally great so far but requires a totally different tune. It's not fun always being worried about blowing a MAF. Makes you not want to take the car anywhere far.

 

I think that I got mine from Suncoast.

It seems from Pete's post that the Bosch 44 doesn't have the venturis. Those are needed in the AWD car to draw the fuel from the wings around the front diff. He has the C2 tank, so no wings on the sides.

Does your fuel pump whine, especially below 1/2 tank? That's one of the signs.

Jon

 

This one is completely stock (for now) ... Have a 2004 Blk 996TT X50 that's done to the T's ... and no issues ... not even a MAF / boostleak.

 

no whinning at that I can hear ... although, there is whinning on gas from the engine compartment, might be steering reservoir from what I understand

 

I had this same issue occur TWICE for me!!! My ECU threw up the EXACT same fault and after replacing the MAF under warranty the issue was NOT SOLVED. It is a fuel supply issue! First time my in fuel tank line was SPLIT, replaced under warranty! Second time it was FUEL FILTER CLOGGED. So as mentioned by someone already, get urself a fuel line, a pump and a fuel filter....she will feel like a new car after!!! I got all those plus a new MAF!! DAMN SHE IS FAST AND SMOOTH NOW!!!

 

Will do that ... just ran with the Durametric ... and it ranged from 1.35 - 1.41 volts .. so I suppose its not the MAF.

It would be nice if the nice people at Durametric would come up with an iPhone / iPad version since its a PITA having a 17" MacBook Pro in the driver's seat to get Actual Values.

I can do the .NET -> iOS conversion if they dont have anyone