Another m10 with idle issues

[4bangerfury]

1985 318i. It started on the way home from work, at a red light the idle would not settle, it just revved. Then when i shut it off and start it back up, it does this:



When driving it now, it either wants to accelerate or decelerate, never just cruise. I checked the throttle position sensor, but it seems like it's working normally when checked with a meter.

I was going to remove the idle control valve and use the screw on the throttle body to adjust it, but mine doesn't seem to have this screw. Can't find it anwhere.

I've run out of patience for this engine to run reliably. Anybody switch out the jetronic injection for a carb? Would a setup like this work for an e30: http://www.ebay.com/itm/BMW-2002-196...-/330938627035

I'm almost positive this is some kind of wiring issue.

Any other ideas?

[4bangerfury]

Here's how she idles after being warmed up. It reminds me of how it used to idle before I found an idle air valve and controller. I followed the instructions in the bentley to check both of those parts with a meter and both seemed to check out.

[4bangerfury]

Tried the penny trick. It runs almost as well as it did before. I'll delve into this more once i get the parts to make a smoke machine and really check for vacuum/intake air leaks.

I'm pretty sure this rules out the idle stabilization relay. It would suck if that failed already.

[bullywagon]

Might want to replace the o2 sensor. A surging idle when warm is a sign of a bad one. They are pretty cheap and easy to replace if you have the removal tool.

[packratbimmer]

Its sucking air. The ECU is not adaptive so you must relentlessly track down all vacuum leaks.

Intake gaskets, injector O-rings, valve cover gasket, valve cover breather hose, air boot, all vacuum hoses, vacuum hose plastic fitting, dip stick O-ring, dip stick to block seal, brake booster hose, throttle body gasket, cold start injector O-ring....etc.

Once you seal up the vacuum leaks, use the "penny trick" if the idle valve and idle valve module are not working.

Good luck