HELP problems with idle speed HELP

[smity]

i have been having problems with my 190e it all of a sudden wouldn't idle so i had a look and if i tightened the excelerater cable then it ran fine but the throtle wasn't going all the way back down and hitting the sensor now i have change the idle speed using the screew but it idle just right when in drive and stopped at the lights with break on so it wont go no forward on its own but when in neutral its to high bout 1500rpm whats wrong could some one please help thanks

 

[LAMAR]

Remove the black cover behind the battery. behind that is a silver relay,the overvoltage protection relay its may have one or two fuses in the top check to see if any have fused if so replace the fuse and then reset your throttle cable back

 

[MondeoMan]

This sounds like the symptoms of a failed/stuck idle control valve. This maintains air flow when the throttle is closed to control the idle speed; by adjusting the throttle to be permanently open you've gotten around it, but it won't run correctly.

I'm not intimately familiar with the 190, but the valve is usually cylinder shaped, with 2 small hoses connected to each side of the air intake next to the thottle spindle, with a single electrical connection. Sometimes they die and need replacing, but sometimes removing them and flushing them out with carb cleaner persuades them to work.

 

[smity]

thank you that sounds like what it could be ive tryed to find it but can't could anyone please send a picture of where it is?? thanks

 

[smity]

i taken off what i think is the idle control valve it has a screw on top to change the idle time (is that right) and it is very blocked so im going to clean it can i let it soak in brake fluid??

 

[flagstaff]

soaking it in brake fluid would almost definitely be a *bad* idea. if there is an 'adjustment screw' on the part you have removed then you almost certainly don't have the correct part. the idle air valve is situated in between inlet manifold branches feeding cylinders no. 3 and 4. it is cylindrical in shape, but held into the manifold in a kind of rubber jacket. it has one electrical connection, and also a (approx 3cm diameter) hose connecting it to the inlet manifold at one end and a similar pipe connecting it to the valve cover at the other. the whole assembly is about the size of a small can of beans.

if you want to soak it in anything, try what one of the other posters said and use carb cleaner.

 

[smity]

thank you for your reply as iam clearly having problem locating this part ive just had another look n im lost!! please please please could somebody send me a picture of what im looking for please this is bugging me

 

[LAMAR]

Only seen idle control valve on 190 16v models
190 idle speed is controled by the feul injection ecu and the idle speed contact switch on the throttle linkage.

 

[smity]

mines a 1986 190e 2.0 with carb not fuel injection

 

[LAMAR]

It won't have an idle control valve if its not feul injection.
Sounds like the idle jet in the carbs blocked srip it down and blow the jets out with compressed air.

 

[smity]

that explains why i can't find it!!if i turn the idle screw up then it will tick over ok in n and d but when ive blasted it round the block for 10mins it cuts out again turn it up more same again!this dunt matter if its hot or cold i can leave it ticking over on the drive to warm up its ok drive it form 10mins it cuts out would this be the idle jet in the carbs??

 

[LAMAR]

Would be a good place to start if you can not see only thing else obvious.
Remove the carb top and carefully remove any jets and clean them with compressed air. don,t poke any thing down them. do them one at a time then replace and do the next jet. clean any carbon deposits inside the carb. Jam open the throttle butterfly carefully an use a soft brush (old toothbrush) and carb cleaner or brake cleaner and clean away all the built up carbon deposits inside the carb. Do it an a carefully methodical manner and should be easy.

 

[smity]

i will do that thank you for the help as i am only a begginer (19) and haven't woked on a merc before will this be a big job??

 

[LAMAR]

Just dont try and rush. it can be a bit fiddly but take your time and dont drop or lose any bits down the carb into the engine and all should be well.

 

[smity]

ok well ill get cracking on that tomorrow thanks again for your help!

 

[andy_k]

mines a 1986 190e 2.0 with carb not fuel injection

it's not a 190E then, it's just a 190. The "E" denotes injection.

Looking at your track record so far smity, I'd suggest you stop taking the car apart until you have got your hands on a workshop manual.

It's so easy to cause yourself more problems when working on an engine you don't fully understand.

HTH

Andy