HEAT + IDLE

[SHIMBIMMER]

Folks,

Does anyone ever experience the idle on their e9 dropping significantly if the car is running for long periods of time in slow moving traffic? To the point the car stalls?

I recently got the valves adjusted and subsequently had to adjust the idle up (thanks again Terry - you are my savior). The car was running very well at around 800 rpms when settled in.

Today in a commute that was way too stop and go in LA heat - the car began to dip down below and eventually started to stall. Am I missing a bigger problem? Do I simply need to adjust the idle again?

Terry helped me recognize that the car is most likely running rich. Any other thoughts?

Cheers,
M

 

[Tyler]

Sounds similar to a problem I had. See the following thread:

http://e9coupe.com/forum/viewtopic.php?t=1696&highlight=

To remedy, I thoroughly warmed up the car on a hot day until the low RPM condition began, then adjusted the idle bypass screw until the RPMs were correct. Didn't take much, and its run great ever since.

 

[SHIMBIMMER]

thanks for that. my biggest fear is trying to remedy something that might be a bigger problem by adjusting the idle. i've only adjusted it once since the valves were adjusted a few weeks ago. It's hot as hell here today - i'll try one more time.

Gotta love our money pits.

 

[SHIMBIMMER]

HEAT + IDLE PART II

OK - I don't want to come off as an idiot (which may be impossible) but this gets a bit odd.

My car is now idling a bit higher then where the idle was set a few weeks ago - even after baking in the sun and sitting in traffic. I didn't change anything from my earlier post. now the car after about 30 minutes of drive time in varying traffic is running at around 900 to 1000 RPM's.

Here's a stupid question. I was dangerously low on gas when the idle dropped down to 300/200 and then stalling. Any way that was causing the problem?

BTW - why didn't BMW put a warning sticker on the car the told us owning one of these was like being concerned for a new born?

 

[jhjacobs]

If I had to guess about your idle speed problems I would suspect that the linkages are worn and that the idle speed is being held by the common idle adjust screw on the cross connect linkage. What happens is that the throttle plates don't always settle to the same place as the temperature changes and even small differences in air flow at idle will dramatically change the idle speed. You might have better luck setting the idle speed (and mixture) individually on each carb (they have an idle adjust screw) when the engine is fully warm. A vacuum gauge is helpful but I used a rubber hose in my ear to listen; I also verify by listening to throttle response. Good luck.