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Old 11-26-2010, 01:14 PM
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bluebee bluebee is offline
Seek to understand,^Value
Location: San Jose, California
Join Date: Mar 2008
Posts: 25,236
Mein Auto: 02 BMW 525i M54 auto 130K
Over here, a misfire turned out to be a bad DISA valve.

Here's what the OP had to say:
"Removed the DISA valve. BMW calls it 'adjuster unit', also have seen it called 'manifold adjuster'. The plastic hinge pin was broken on mine, so the flap was just hanging there inside the intake manifold! What a poorly designed piece of garbage. Apparently, the flap remains closed, restricting air intake, until higher RPM's, then it opens to allow more air flow. The valve is not variable, and is either all the way open or all the way closed. Mine was hanging open - running lean. I was very lucky no parts had flown off YET.
Replaced the valve (BMW - $220), problem solved - car runs great and no more codes!
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