Help problem w/ my 325i

[fmetaljacket]

If I’m cruising between 1600-2500rpm once in a while the car seems to forget that my foot’s on the gas this happens more often when i’m at the same speed or when i slow down. When it does this rpms drop down to idle (~700) and then it wakes up and goes back to where it was before but if I press on the gas before it gets to idle it will wake her up but the car gives a mean jerk when it wakes up. It happens alot at ~1700rpms but only if I slow down or keep the gas really steady if I'm accelerating it wont happen.

This problem really stumped me i don't want to throw any parts at her until i get a better idea of what's causing this... I've had a friend suggest the mass air flow sensor might be the problem or knock sensor. I’ve changed spark plugs and fuel filter with no success this week. I might be wrong but the car seems weaker than before i remember my head getting jerked back when accelerating. Any ideas?

Background:
1994 325i E36
Only happens between 1600 and 2500rmps
Happens in every gear even neutral
Car idles fine not erratic
Not affected by hot or cold weather or A/C

[bimmerguy82]

Originally Posted by fmetaljacket

If I’m cruising between 1600-2500rpm once in a while the car seems to forget that my foot’s on the gas this happens more often when i’m at the same speed or when i slow down. When it does this rpms drop down to idle (~700) and then it wakes up and goes back to where it was before but if I press on the gas before it gets to idle it will wake her up but the car gives a mean jerk when it wakes up. It happens alot at ~1700rpms but only if I slow down or keep the gas really steady if I'm accelerating it wont happen.

This problem really stumped me i don't want to throw any parts at her until i get a better idea of what's causing this... I've had a friend suggest the mass air flow sensor might be the problem or knock sensor. I’ve changed spark plugs and fuel filter with no success this week. I might be wrong but the car seems weaker than before i remember my head getting jerked back when accelerating. Any ideas?

Background:
1994 325i E36
Only happens between 1600 and 2500rmps
Happens in every gear even neutral
Car idles fine not erratic
Not affected by hot or cold weather or A/C

I would say maybe a vacuum leak issue but if it idles fine, then maybe it's more of a fuel issue. test your fuel pump and pressure regulator. When was the last time you changed your fuel filter? Run some Sea Foam cleaner through your tank.

[fmetaljacket]

Fuel filter was just changed... how would i test the fuel pressure regulator and pump
thanks for the reply

[saylee]

i think you should run a whole fuel system cleaner from autozone..then let your car idle for a lil bit then run it agian and see if it happens and if it does then check it out...but the vac lines can cause that..

[thekid]

I would go with 44k not just some generic stuff. There are two kind of 44k, one is in a can that goes in your gas tank and the other you hook in directly to your fuel system. Either one works great.

[saltshaker185]

i would take off your throttle posistion sensor and clean it real well with electrical connection cleaner... it could be telling your engine that the throttle is going back to idle and your computer would be cutting fuel to your engine as a result of this...