Author Topic: Acceleration issues (Read 2619 times)

bigalrut · « **on:** December 23, 2010, 06:05:45 PM »

Just experienced acceleration issues in my '91 318is. The car idles and runs fine except it feels as though the engine is stumbling when I accelerate. Anyone have any suggestions?

dkbmxer002 · « **Reply #1 on:** December 23, 2010, 07:05:22 PM »

is it like it is "skipping" under full load? usually at speeds above 50? if so thats exactly what mine has been doing. it usually only does it once the car has gotten warm. i am assuming that it is the maf going bad or reading poorly.

bigalrut · « **Reply #2 on:** December 23, 2010, 07:22:01 PM »

Yeah...have you had any luck troubleshooting the MAF? Mine will also "skip" while I rev up the engine in neutral.

Brian · « **Reply #3 on:** December 24, 2010, 03:15:46 AM »

Check for air leaks around all of the hoses on the inlet manifold side

dkbmxer002 · « **Reply #4 on:** December 24, 2010, 03:26:06 AM »

nope. not much to do as far as i know except replace... but i am sure someone with more knowledge on here can give a better answer.

DesktopDave · « **Reply #5 on:** December 24, 2010, 07:08:03 AM »

Do a stomp test, see if it has any codes stored. It likely won't, but you never know. Stumbling like that could be caused by an over-rich condition from a bad FPR or thermo sensor, a lean condition from the O2 or AFM, a flaky coil, etc. The stomp test might give you a good point to start.

I'd grab my multi-meter & go through the usual culprits:
Cam & crank sensor resistance
Coolant temp sensor resistance both hot & cold
AFM resistance & AFM IAT sensor
O2 sensor volts & resistance IIRC.