just had big end done crank reground new bearings since picking up has developed a missfire below 2000rpm, runs rough on idle.
Mar 10, 2010 at 8:55 AM
1999 BMW M3 miss fire
1999 BMW M3
PAUL POWDRILL
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Without more information, all I can say is, go back and find out what you did wrong.
Mar 10, 2010 at 10:13 PM
[quote:b491a4c6d2="paul powdrill"]Engine Mechanical problem
1999 BMW M3 6 cyl Two Wheel Drive Manual 122000 miles
just had big end done crank reground new bearings since picking up has developed a missfire below 2000rpm, runs rough on idle.[/quote:b491a4c6d2]
I think what you are saying is that you had a shop rebuild the engine and reinstall it, and now you have a misfire below 2000 rpm. My guess would be a vacuum leak associated with all of the emissions plumbing underneath the intake manifold. It's hard to get to and easy to leave a hose disconnected. The shop probably left something like the vacuum line to the vapor cannister unplugged. I've always had trouble getting that stuff back together right. Fortunately, I've always had a second car around to compare to and help me remember where everything goes. Even then, it's tough to get to it. At the very least, you'll have to pull the traction control unit and the throttle body off to see under there.
Good Luck
Dr. Loot's Assistant
1999 BMW M3 6 cyl Two Wheel Drive Manual 122000 miles
just had big end done crank reground new bearings since picking up has developed a missfire below 2000rpm, runs rough on idle.[/quote:b491a4c6d2]
I think what you are saying is that you had a shop rebuild the engine and reinstall it, and now you have a misfire below 2000 rpm. My guess would be a vacuum leak associated with all of the emissions plumbing underneath the intake manifold. It's hard to get to and easy to leave a hose disconnected. The shop probably left something like the vacuum line to the vapor cannister unplugged. I've always had trouble getting that stuff back together right. Fortunately, I've always had a second car around to compare to and help me remember where everything goes. Even then, it's tough to get to it. At the very least, you'll have to pull the traction control unit and the throttle body off to see under there.
Good Luck
Dr. Loot's Assistant
Apr 5, 2010 at 1:41 AM
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