Idle problems

[white190]

HI all

I finally got my new Idle control valve from the stealership (after desribing the symtoms to them they said i needed a new valve)

I've fitted it the engine no longer dies when it is cold but still my idle is 1500-2000rpm when the engine is hot and in Park and ~500-600rpm when it is cold......please don't say I've wasted 130 pounds on this valve for nothing.

Strangley enough when the engine is warm if I unplug the air flap possition sensor the Idle returns to ~1000rpm. nice and steady.

whats going on....

Any ideas people...

Also it make no difference if i have the EHA plugged in or not....

have any of you had this problem before??. What cured it.?.

 

[steveLAWSON]

http://www.mercedesservicing.com/contact.asp

I HEAR HES THE MAN .

 

[Andy]

Hi

I would check the idle speed position sensor on the side of the air flow sensor and the throttle valve switch plugs have not been mixed up.

Personally I wouldn't of parted with £130 of my money before having the vehicle checked out. Might just conincidence as to why it does not cut out in the morning know.

Good  luck anyway.

Regards

Andy @ www.mercedesservicing.com

 

[white190]

Thanks Andy I'll check that.

130 quid loss.....serves me right for listening to the Stealership dudes....they've got it wrong several times in the past........I guess I was just hoping for a quick fix....ah well......any one need a used Idle speed control valve.

 

[kiwi_bloke]

At last someone has my problem!!

hey! Ive got the same problem. Thought id let you know what i tried:

timing
mixture
new air filter
cleaned idle control valve
cleaned breather pipes
checked idle 'switch'
checked relays
cleaned air intake manifold

None of these did any thing for me!!

If you fix your problem give us a bell and let me know what you did...im really curious....

 

[white190]

well my Idle problems seem to have gone.....at least for the moment....fingers crossed.

Turned out I had a intermitently bad decell/Idle switch and the inline valve in the breather pipes was blocked.......took the switch apart and cleaned it ....fitted new inline valve and new breather pipes (cos they looked nasty).......fired up car and it idled normal striaght away.....woo hoo.

 

[kiwi_bloke]

i wish it was as easy as that!

time to take my trusty steed into the "stealership" hehe last resort! ive done everything possible to fix it...cleaning the idle valve fixed it for a month....they seem to think they wanna charge me 600 new zealand dollars for a new one.... ah ill have something to say about that...i priced one for 250...trying to rip us merc owners off..what do they take us for! lol

cheers

josh

 

[white190]

your not kidding merc Uk wanted 130 pounds for a new Idle control valve but Eurocarparts eventualy got me one for 80.......


Have to replaced your OVP and the little brownish white inline valve in the breather pipes ??.

 

[kiwi_bloke]

so many things so little time

no i havent changed the brownish white valve... but i did check the ovp and clean the relay contacts ect...ive got a sneaky suspision it may be a bit of crap getting in the system somewhere (hopefully) ... what i have noticed though is the engine revs excesivly on start up on occasions (4000) and wont right its self until being restarted....upon doin that the car pinks ALOT until its let to cool then restarted. Im thinking it could be a vaccum problem or electrical....its not the throttle cable....

cheers

josh

 

[white190]

have you cleaned the 'air flap' (large round inlet flap under the air filter)....if theres any crap on this it can screw up the Idle big time...

Have you checked the crank position sensor and cleaned it's plug (the plug is under the air filter ... it only has 1 shielded wire)...this can cause ignition timing problems if the shielding starts to break down or if the connector has a high reistance.

clean out that inline breather valve.

Your simptoms are exactly what I had.

 

[kiwi_bloke]

fixed! hopefully itll stay that way

just thought id let ya know my idle problem disapeared! hehe new idle valve, cleaned the air mass meter, readjusted flap, timing, mixture, idle speed and the oxygen sensor got reconected...

fired her up great! just a tiny bit uneven (100 rpm) im not too worried. When its cold tho it idles at 1300 rpm...normal? yes apparently....

cheers!

 

[demetris]

revs

Yeah me too my 1987 190e 2.0 auto carb does nutty things too, given up now, when you fire it up from cold reaches 1200rpm, then put it in d and it hits 750 but let it idle at the lights for 3 odd mins and the revs drop and that is it, had 3 different mechanics check it out and they are all stumped, the only way round the issue is to put it in N when the revs start to drop and then back to D when I am ready to move can't be that good but hasn't failed me yet in 2 years.