Engine erratic on 190E

[StevieJB]

Wonder if anyone could diagnose this problem.
Sometimes when I take my foot off the gas at about 1500rpm I get surging from 12500rpm to 1500rpm until I stop or I put my foot back on the gas slightly. when I do stop then the revs stay at about 1100rpm. Other times the car is fault free, revs on stop are 750rpm. I even cleared it once by restarting the car. I have cleaned the Idle valve and all the pipes/breathers going to it. Could it be the switch on the throtle cable stop, being faulty. I have tested it with an electrical tester and it seems fine. If it is the Idle valve wouldent it do this all the time?
hope someone can help

 

[television]

http://www.detali.ru/cat/oem_mb2.as...&L=765.902&CT=F&cat=500&SID=54&SGR=045&SGN=03

It will be the OVP relay item 149 in the above.

they get poor soldered joints and go intermitant.

malcolm

 

[StevieJB]

Thanks for the prompt reply. It looks like a fuse in the top of a relay. Is that the part I need or is it all of the holder thing (146). I take it that this is in the fuse box.
This is off the thread slightly but does the blower slide switch have a resistor for the first two speeds? Mine works OK on speed II upwards only.

 

[television]

It is the relay with the fuse on top. re heater there is a resistor bank attached to the blower, sometimes it dirty contacts on the switch. the resistors are all standard parts,obtained from RS or CPC .

Malcolm

If you are any good with a soldering iron you could try and solder up the OVP relay

 

[mike65]

Could it be the switch on the throtle cable stop, being faulty. I have tested it with an electrical tester and it seems fine. If it is the Idle valve wouldent it do this all the time?
hope someone can help

I has something like you descibe and fixed it by tweaking the black threaded stopper thingy on the cable.

Mike.