Posted by Karl Koenig on September 04, 1998 at 00:47:14:
In Reply to: Re: rough idle posted by Peter Florance on September 03, 1998 at 20:53:01:
: : Here's something for all you fuel injection gurus to mull over:
: : I have installed an m535i engine in my 81 528i, but have kept the original l-jet injection system (Ca. smog laws *#%$#). Now based on advice from this page i had the oxygen sensor disconnected for a richer mixture. The other day i reconnected the 02 sensor for a smog check. My idle became much rougher, but acceleration became better! How about that?
: : dadbeh
:
: Maybe it running too rich in mid throttle and the sensor is correcting? Why it runs rougher at idle I'm not sure....
Had the same idle in my car (sort of lumpy) before and after installing a 535 engine in my car. I arbitrarily backed off the spring on the air door 3 clicks. Recently I found an old copy of Jim Rowe's book on fuel injection. Will have to work through that some day, after Momma's car is all perfect again.
Anyway, I put the original 528i intake and exhaust onto the 535i engine. The idle had exactly the same characteristics, and mid range acceleration has the same annoying sound -- like pinging -- but only around 4000RPM.
You mentioned California. Check with Carl Nelson in La Jolla. He was helpful to me. Phone number is in the Roundel tech advisors.