so confused, idle has a mind of its own. - PeachParts Mercedes-Benz Forum

GregoryV022 · #1 09-28-2009, 12:43 AM

my 190 16 valve has the strangest idle problem i have ever seen.

it follows no patter what so ever so im not even going to try to describe one.

but i can tell you that it idles as high as 2500 RPM or as low as 600. at 600 its almost dying.

most of the time it stumbles on the start up. like its missing a few ignitions. but after i give it some gas. it smooths out but then the above problem kicks it.

i replaced all the injector seals because they were old and dry and were letting air by. i checked my pouring water over the injectors. the engine coughed and spluttered.

but i am completely at a loss for the idle behavior of this car. and seeing as its supposed to be a highly tuned German racer. i embarrass my self when i drive it.

Bill Adkins · #2 09-28-2009, 08:50 AM

I believe there are two switches involved in the throttle linkage, there may be an issue there
Bill

GregoryV022 · #3 09-28-2009, 07:37 PM

thread bump

tinypanzer · #4 09-29-2009, 06:39 PM

I see that you had vacuum leaks in your injector seals. Is it possible that somebody richened up the idle mixture in order to compensate for that? If so, then fixing the problem reveals the bad adjustments. Is your lambda tower still sealed, or has it been opened?

Also, check to make sure that your throttle linkage is adjusted properly, and moreover, that the idle switch is engaging when you take your foot of the gas. First check the switch for visible activation, then pull off the wires and hook up a meter and make sure that the switch electircally opens and closes as it should.

GregoryV022 · #5 09-29-2009, 09:06 PM

Quote:

Originally Posted by tinypanzer

I see that you had vacuum leaks in your injector seals. Is it possible that somebody richened up the idle mixture in order to compensate for that? If so, then fixing the problem reveals the bad adjustments. Is your lambda tower still sealed, or has it been opened?

Also, check to make sure that your throttle linkage is adjusted properly, and moreover, that the idle switch is engaging when you take your foot of the gas. First check the switch for visible activation, then pull off the wires and hook up a meter and make sure that the switch electircally opens and closes as it should.

well i doubt somebody richened the idle mixture but its not out of the question. how would i go about checking that.

and about the lamda tower. no idea what that is. (i guess i don't know as much as i think i do). but again. help in checking.

the idle switch i will check ASAP.

i also just remembered that i am running very old spark plugs as far as i am concerned. will pull those and check their condition ASAP

GregoryV022 · #6 09-30-2009, 12:15 AM

im taking the car in tomorrow. as it didn't pass SMOG in California. ??? i might just pay money to have them get it running like new and then maintain it from there.

i found an awesome shop in Burlingame in the bay area called ********e Shmid. and i know they understand Mercedes of our era because they have a freaking warehouse full of classic Mercedes.

some of them are for sale. i might buy a mid 70's 190D from them. in great running order just needs to be cleaned up

tinypanzer · #7 10-05-2009, 09:24 PM

Quote:

Originally Posted by GregoryV022

well i doubt somebody richened the idle mixture but its not out of the question. how would i go about checking that.

and about the lamda tower. no idea what that is. (i guess i don't know as much as i think i do). but again. help in checking.

the idle switch i will check ASAP.

i also just remembered that i am running very old spark plugs as far as i am concerned. will pull those and check their condition ASAP

The Lambda tower is a metal tube that sits between the air meter intake and the fuel distributor. It lines up with the grommeted hole on top of your air cleaner housing. If it has a metal BB lodged in it, then it has never been monkeyed with. If the BB is missing, or the top of the tower sawed off, then it has.

GregoryV022 · #8 10-06-2009, 08:07 PM

Quote:

Originally Posted by tinypanzer

The Lambda tower is a metal tube that sits between the air meter intake and the fuel distributor. It lines up with the grommeted hole on top of your air cleaner housing. If it has a metal BB lodged in it, then it has never been monkeyed with. If the BB is missing, or the top of the tower sawed off, then it has.

the car is with the indy right now. ill check it once it gets back.

as far as checking the idle switch. how would i go about doing that. i have a multimeter just very little practice in how to use it.

tinypanzer · #9 10-07-2009, 05:07 PM

Well, let's see what your indy says and what he's able to fix. Then we'll dig into that.

GregoryV022 · #10 10-07-2009, 09:37 PM

Quote:

Originally Posted by tinypanzer

Well, let's see what your indy says and what he's able to fix. Then we'll dig into that.

my indy is replacing the plugged pre-cats. for $1000. that seems like a bit much.

Bill Adkins · #11 10-07-2009, 09:40 PM

The cats will cause a lack of power and if really restricted a poor idle or hard start but shouldn't have as much effect on varying of idle speed
Bill