M50TU swap stumbles / miss

[BronzitCab90]

My 1995 m50tuB25 stumbles / misses at very light throttle. Typically in 3-5 gears. I think it's the tps and plan on checking the values tomorrow after work. Any other ideas.


Specifically when using VERY light throttle to maintain a moderate cruise speed the engine develops a missfire which results in a jerking motion from the car until the clutch is pressed.

[MattM]

spark plugs?

[BronzitCab90]

spark plugs?

They are clean, but not new. I may change today just because.. What's the best recommended plug for the M50?

[99em1]

when it starts bucking or jerking does the front end dive as if you hit the brakes? when cycling up the first three gears does it feel rough when you disengage the clutch instead of smoothly rolling into the next gear?

I had this issue and a"new" tps fixed it. afaik any e36 tps will suffice so its an easy, cheap junkyard fix. I was also throwing an intermittent tps code FYI.

[BronzitCab90]

when it starts bucking or jerking does the front end dive as if you hit the brakes? when cycling up the first three gears does it feel rough when you disengage the clutch instead of smoothly rolling into the next gear?

I had this issue and a"new" tps fixed it. afaik any e36 tps will suffice so its an easy, cheap junkyard fix. I was also throwing an intermittent tps code FYI.

Sounds about on the nose description of my issues. How do u pull codes from the m50 DME?

[99em1]

Put the key in position 2, stomp the gas pedal 5 times. I think you get one long CEL flash then it starts sequencing codes if there are any. Haven't done it in a while but this link should have everything you need.

http://www.bmw4life.com/stompTest.htm

Just for giggles why not clean your maf while you're at it. Probably won't solve anything but it takes like 10 minutes and doesn't cost you anything.

edit: to answer your other Q, when I change the plugs the ones I put in are NGK BKR6E gapped to .032 (s50). Don't think it's your plugs though.

[JdmEuroNorth]

They are clean, but not new. I may change today just because.. What's the best recommended plug for the M50?

Clean doesn't mean shit if they aren't properly gapped.

[BronzitCab90]

Clean doesn't mean shit if they aren't properly gapped.

Very helpful. You could have specified the gap or answered a question about the proper plug....

Poorly gapped plugs probably wouldn't create the situation we are discussing here anyway

Just sayin.

Anyways, unplugged tps and untwisted the wires, since they were at an odd twisted angle and plugged it back in. So far so good. Could still be a bad sensor.