fast idle not fast enough - PeachParts Mercedes-Benz Forum

ggenovez · #1 12-11-2006, 12:26 AM

Hi all,

I have a 72 250 M130 w/ dual zeniths.

My problem is the fast idle is not fast enough. The front screw is all the way in and I'm ideling at 1800-2000 RPM's. That's the the vacuum on the advance.

Any ideas on how to increase it?

I was thinking of setting it to fast idle, then turning the idle screws until I reached 2500 RPM then backing off the idle stop screw to 800 without the fast idle.

Any ideas?

Thanks

barry123400 · #2 12-11-2006, 10:42 PM

The fast idle adjustment is in relationship to the fast idle cam I think. Try to get a copy of the haynes manual or look into the archives on this site. It strikes me you might be taking the wrong approach. I could easily be wrong as it has been a long time since I set these up. Others with more knowledge will post but do have a close look in the archives. The information will be there I believe.

ggenovez · #3 12-11-2006, 11:23 PM

Thanks Barry,

I did have a look at the archives. The procedure to set it is there but I can't find anything like my problem my fast idle screw has bottomed and I am at 1800 RPMs, Enigine hot, vacuum on advance.

ctaylor738 · #4 12-12-2006, 04:56 PM

What are you trying to do or fix?

Are you trying to set the fast idle for start and warm-up, or are you trying to set the hot idle speed?

1800 is on the high side for fast idle.

ggenovez · #5 12-12-2006, 08:35 PM

This is the cold start fast idle speed. Job 07-33 has the specs for US cars to run at 2500-2700.

I'm just trying to set it right.

ctaylor738 · #6 12-12-2006, 09:22 PM

I thiink that's nuts. Unless you're in Winnipeg, 1200 or so at cold start should do it. The manual may be saying that you need 2500 hot to get 1200 cold, but I doubt you would get that much of a drop.

I would mess with the fast idle adjustment to get an idle speed that keeps you running smoothly when you shift into gear after a cold start.

If you are having trouble with stalling when cold, I would look into the choke position and the pull-down adjustment.

ggenovez · #7 12-12-2006, 11:17 PM

Thanks Chuck.

I guess I should shoot for 1200 cold. I guess that's in park. correct?

Personaly I don't think 5000 RPM is enough for Winnipegs winters, but that's just me.

Thanks