Help diagnose: Air or fuel starvation

dbjb · 08-10-2010, 09:31 PM

Need help guys...

A friend of mine has an 07 335, dci and jb3 2.0 on map 3. New 943 pump 5k miles ago. No other performance mods.

The car has been running fine but lately it feels as if its starving for either air or fuel. When I press the gas pedal 0-75%, the car picks up just fine. However, when I depress the pedal 80% or WOT, it feels as though the car struggles to pick up speed. I can hear the exhaust trying hard to suck in air. Once I experience the symptom, if I release the pedal a little, the car starts picking up speed quickly again.

What the heck is going on? The stock intake is going back on to see if that resolves the problem. If not, I can only imagine its the injectors, the pump, fuel filter, or ???

What are your thoughts? Thanks in advance.

Sniz · 08-10-2010, 11:04 PM

tell your friend....err you to check for collapsing intake piping. Ive seen it happen on a few different platforms. Would be strange on this car as it has 2 disected intake tracts once you have removed the OEM airbox though.

dbjb · 08-11-2010, 10:16 PM

Well, switched from DCI to stock intake plus K&N filter. No more problems. Strange, but maybe it was in fact collapsing. I dunno. Guess its time to finally pull the trigger on a CAI.

08-10-2010, 09:31 PM	#1
dbjb I sweat pheromones 206 Rep 2,103 Posts Drives: e92 335i, retired SLK55 Join Date: Jul 2009 Location: NorCal iTrader: (25)	Help diagnose: Air or fuel starvation Need help guys... A friend of mine has an 07 335, dci and jb3 2.0 on map 3. New 943 pump 5k miles ago. No other performance mods. The car has been running fine but lately it feels as if its starving for either air or fuel. When I press the gas pedal 0-75%, the car picks up just fine. However, when I depress the pedal 80% or WOT, it feels as though the car struggles to pick up speed. I can hear the exhaust trying hard to suck in air. Once I experience the symptom, if I release the pedal a little, the car starts picking up speed quickly again. What the heck is going on? The stock intake is going back on to see if that resolves the problem. If not, I can only imagine its the injectors, the pump, fuel filter, or ??? What are your thoughts? Thanks in advance.
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08-10-2010, 11:04 PM	#2
Sniz Lieutenant General 661 Rep 10,587 Posts Drives: e92 335 - gone // e36 M3 turbo Join Date: Mar 2007 Location: Ellicott City, MD iTrader: (1)	tell your friend....err you to check for collapsing intake piping. Ive seen it happen on a few different platforms. Would be strange on this car as it has 2 disected intake tracts once you have removed the OEM airbox though. __________________
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08-11-2010, 10:16 PM	#3
dbjb I sweat pheromones 206 Rep 2,103 Posts Drives: e92 335i, retired SLK55 Join Date: Jul 2009 Location: NorCal iTrader: (25)	Well, switched from DCI to stock intake plus K&N filter. No more problems. Strange, but maybe it was in fact collapsing. I dunno. Guess its time to finally pull the trigger on a CAI.
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