912E idle problems (L-jectronic)
 

I'm getting crazy and I need help.

The engine is running perfectly (no loss of power, acceleration OK, consumption OK,..) BUT the idle speed is too high and stable.

Even if i turn clockwise to the maximum the screw to tune the idle to the min, I still have 2.000 RPM.

Fondamentally no change wathever the position of the by pass screw of the air intake sensor (a little bit higer when getting less reach compared to the max).

By pass air flow completely close and idle speed tuning screw completely close : +/- 2.000 rpm

If I completely close the "input" of the air filter box, I loose 100 or 200 rpm but still running too high. (I don't know how enough air can enter in the injection but I have no "leak" (I mean undesired air input somewhere in the injection)

BUT if I disconnect the input of the auxiliary air intake (air can enter directly and not from "after" air filter and air intake sensor); the speed fall down. If i place close this input with my finger, it's running too high and I feel that air is aspired by this input. If I let some air enter, speed is sligtly falling until motor stop wen fully open.
I'm getting crazy so if anybody has an idea...


Thanks

You may have more luck by posting this on the 912 forum.
I found with my 912e air leaks caused the most problems, it sounds like your intake boot has a crack in it.
Try this link to a troubleshooting guide.

the air regulator probably is not closing when it warms up. clamp the hose to test it. also, disable the deceleration valve. it may be faulty. just pull off the small vacuum hose and plug the hose.

This may sound funny, but you ought to ask the guys over at 914club.com. They are type-4 experts.

-Britain

the largest group of 912E owners you can reach via the internet is at "912 registry" (check Google)....the above entry is also correct in that the 914 1.8 & the 912E (2.0) type IV motors both have the L-jetronic Bosch EFI systems....

Happy hunting

P.S. I am an 'ex' 912E owner & HIGHLY recommend that you join the 912 registry....tons of info & GREAT people!!!! I don't even own any 912's now..(911S Targa) but am still a welcomed member of this group...

Greg