Fluctuating idle - Benzworld.org

Guest (MBNZ) · 07-13-2001, 06:00 AM

In the last couple of days, after my 10 minute drive to work in the morning, the idle on my 87 300E will go up to 1600 then back to 600, back to 1600, then back to 600 etc., every two seconds. I cleaned the micro switch at the throttle linkage, didn't help. Someone said it might be the thermostat stuck open. Any help would be appreciated. Thanks.

Guest (MBNZ) · 08-01-2001, 08:24 PM

I had this problem a few months ago. Try your Idle Valve (Part No.14-004, PerformanceProducts,com). It's located at the front of the block, just under the air filter canaster, in front of the Fuel Dist. This babe will run you about $175, but replacing it solved my problem. (By the way, I had to have a Dyno test ran to get this Info.)

Guest (MBNZ) · 08-16-2001, 07:56 AM

Jason, Thanks for responding. I removed the idle valve and cleaned it but the problem persisted. Now the problem only occurs maybe once or twice a week. It doesn't seem to do the occillating thing anymore, now the idle goes a little high and stays there. Did you try to clean yours before you repaced it?

Guest (MBNZ) · 08-24-2001, 01:16 PM

Unfortunatly, I did not. But, I've also had to replace ( by replace, I mean rebuild... have you seen the prices on the new ones... OUCH!!) the second of the two feul pumps. Now the car runns like a champ! I feel sorry for any M3's or 535's I find on the road now...

Guest (MBNZ) · 10-12-2001, 03:54 AM

Jason, As of today, I have not had any trouble with the idle for the last six weeks. the car's been running beautifully(knock on wood, of course) After I cleaned the valve, it still oscillated but a number of highway miles seemed to clear up the problem but who knows.

jsolano · 09-25-2003, 08:21 PM

Pete,

Looks like you had this problem:
My engine RPM goes up and down, It gets better once I put drive and start driving. But as soon as I stop and switch it to either P or N, starts oscillating again, it goes from 500 to about 2200 rpms. I also feel misfiring once in a while.

Any suggestions ?? I read you cleaned-up a valve ? what is the name?
I have the marc CDs, would you point me out to the file that have this procedure.

THANKS a lot in advance.>!

Regards,