190D 2.2 Low Idle and No Tach - Page 2 - PeachParts Mercedes-Benz Forum

DieselPaul · #16 03-03-2014, 12:47 PM

Talked to my friend with the smoke machine, we are going to leak test it when I get the 190D back up here. The 92 2.5 I put together for my sister won't charge, and my sister has my dads Lexus, so he needed a car. My 87 300d is at the bodyshop (sister hit a parking block and moved the radiator), and all the other cars are rust free southern cars I put away for the winter so I went out and bought the 190d as something that was ugly but a consistent spare car. And then I had to go and break it lol.

ROLLGUY · #17 03-03-2014, 07:20 PM

Quote:

Originally Posted by pawoSD

The om601 does not have an electric idle controller at all, it has a vacuum adjuster that can raise the idle by about 100RPM when the A/C is on....that's it. The idle is mechanically set, and can be switched between "normal" and "raised" by applying vac to the little solenoid on the IP. On mine I plumbed the line to be always under vac to keep the idle higher just because its smoother at 750rpm than 600-650ish.

That is interesting, because I had a 1985 OM601 that had a solenoid where the vac pod would be on the end of the IP. I just assumed that it was fed the electrical signal instead of the switchover valve.

DieselPaul · #18 03-04-2014, 08:10 AM

Would that be the big red solenoid with the two pin connector on the top of it? If that's the case this '85 has an electronic solenoid as well.

pawoSD · #19 03-04-2014, 11:49 AM

Weird....maybe they added that to late OM601's. Mine has no electrical connections at all on the IP. Just the idle adjuster and shutoff, both are vacuum. Mine is one of the very first engines, its serial number is only #3,188 I believe.

DieselPaul · #20 04-25-2014, 02:40 PM

Finally got this car back from my dad, he's put 6,000 miles on it while I've been busy with work and school.

Following the link from ah-kay
'84 190D, EGR Module..???

I jumped the two pins under the Klima like he did in the thread. My tach kicked on and my idle is good around 700rpms.

So if the tach is working, and its idling right, that means my idle control relay is good, and my crank sensor is good.

So I wonder what is messed up then.

I have removed Klima's from cars before, and replaced the a/c end of it with an ice cube relay with no Ill effect. Do you guys think leaving those two pins jumpered and putting in an ice cube relay for the A/C will hurt the car? I do not generally like shortcut fixes, there is still something wrong with the car, but having the idle up makes the car drive nicer for the time being until I actually sort it out.