This is a part open throttle or trailing throttle condition. The engine simply bucks like the throttle is being abruptly closed at 80 mph - again if the throttle is trailed slightly.

If I hammer the throttle, the condition goes away. If I turn the AC on, it goes away. Any thoughts?

 

mileage on your JWC?

also have you noticed a drop in fuel econ. lately?

 

Are you in 2nd gear? That's the rev limiter.

 

 

Nice, hit a man when he's down...er stumbling.

105,000 miles

 

so .... at the same rpms, say what?3500 ? if you're in say 2nd or 3rd , it doesnt happen when lifting off the throttle? it's only when in overdrive?

 

Exactly. And, this condition appears to go away if I turn the AC on; I tried this experiment thinking that some additional load on the engine might mimic more throttle.

Maybe the drive-by-wire throttle is off a bit.

There are hints of this stumbling or cutting out if you will occasionally when the throttle is near closed. I sense this while driving and this is fairly new.

Maintenance on the engine is fairly normal; oil changes every 3,000 - 5,000 miles, air filter changed in spring - this is a JCW car - and JCW spark plugs 50K miles ago. Coolant was changed twice in 105,000K miles. Nothing else was done...

 

Meb if the MAP sensors have not been replaced you may want to look into that, also if you have not changes the two O2 sensors its time to replace those also. I put 154K on THDUKE and towards the end those sensors were the cause of any issues that I had, I am now at 172K and running strong with the new engine that was replaced at 154K

 

- new engine!!! What happend? I haven't seen you at the track...was the engine the reason?

 

Had rings and rod bearings job done by Don at DMH in January lasted 400 miles before it blew up on the LIE, had Habberstad BMW put a new engine in and all is working now. Did not get alot of track time in early this year because of that, I am now getting back on schedule once more.

 

Michael,

Don't know what to say. Do not drive my car. I don't need anymore bad luck. (joke, joke)

Am having problems when I coast on closed throttle such as coasting down on a freeway exit. My engine will sometimes die and then easily re-start. And, the engine stopped twice on the main straight under full throttle. Gads ! Have the CAT out for track days and, of course, throwing CEL codes. Don't remember having problems when the CAT is in on the days when I'm not tracking. Makes me paranoid about touching anything on the engine for fear of upsetting some ECU delicate balance.

John Petrich in Seattle

 

I'll make an appointment with BMW to have this checked out. There are no codes showing up, so hopefully the OBDII diagnostics have a record of this???

When I leave cars alone they perform flawlessly for a couple hundred thousand miles. As soon as I touch a car, or even begin to think about playing, it begins acting up. Perhaps the order of the world is out of since with my aspirations...

 

Michael,

Know what you mean. And worse yet, when the wife starts making the same connection. No peace forever.

John Petrich in Seattle

 

...thought my wife was one and the same...they have a power that is uncanny...they seem to just know when we've got the bug to play

 

Are we just children or true masters of the houshold?

John Petrich in Seattle

 

I long for a wife whom loves 1g turns, thinks zero to sixty in 5 seconds is slow and knows that the word cute is just another word for sleeper. But then, I would be car broke I'll keep my gal for better or worse!