[W126 Coupe] idling issues

[Gary Peck]

Richard

Have you checked your OVP relay, I experienced a similar problem on my 88 
sec euro, the circuit boards can go bad, either re-soder or replace, try 
swapping out one first.

Yours truly

Gary Peck
----- Original Message ----- 
From: "Richard Hogarth" <R_Hogarth at Foundrycove.com>
To: "'Dan Gardner'" <cruftsk9 at tpg.com.au>; "'Mercedes Coupes Mailing Lists'" 
<mbcoupes at mbcoupes.com>
Sent: Sunday, April 08, 2007 4:09 PM
Subject: Re: [W126 Coupe] idling issues



> Dan,

> Many thanks for the kudos and thank you for sharing your experiences below

> in your last email. Now you have hit on something that I can't solve with 

> my

> 560: high idle. The car idles fine when the ambient temp is below 55-60f 

> and

> the car is cold. As soon as the temp gauge hit a hair above 80c,

> the idle in park sits at 1500 and sometimes at 2000. OUCH! That should

> really raise hell with the life of my transmission, not to mention the

> entire drive train.

> I have changed all suspect vacuum lines, temp senders, and all new fuel

> injectors plus seats and seals. I have had the mixture checked and 

> adjusted

> about 1 dozen times. I was also told  that it's within usable spec to 

> which

> I say Bull. Please tell me more about removing the Y tube from the air 

> idle

> valve.

> I have not changed that valve but my local MB shop said that it's still

> good. I've checked, tightened and siliconed every possible place where 

> there

> could be a vacuum leak, I even capped off the brake booster line. I've

> cleaned all of the relay and fuse contacts under the hood. Fuel pressure 

> is

> good although the system does require extra starting/cranking time if I 

> let

> the car sit for more that 2 days.

> I'm miffed on this one.

>

> Happy Passover and Easter to all,

> -RPH

>

> -----Original Message-----

> From: mbcoupes-bounces at mbcoupes.com [mailto:mbcoupes-bounces at mbcoupes.com]

> On Behalf Of Dan Gardner

> Sent: Sunday, April 08, 2007 8:33 AM

> To: mbcoupes at mbcoupes.com

> Subject: Re: [W126 Coupe] modulator adjustment

>

> Hi Folks

>

>    First off,thanks to Dick & Richard for their invaluable help,I have not

> yet road tested the car but fingers crossed I am hoping for a smoother

> change across the shifts.

>    This is the first car I have owned where I had to admit defeat and take

> the car to a German factory trained specialist with 40 yrs experiance. It

> would mysteryously refuse to start and once cut out possibly once every

> three months of use.Each time after an expensive tow home I would get it 

> to

> run although not really analising what the problem was(fuel pressure and

> delivery rate ,sparks to spec) and in the process I picked up a high idle

> and had to remove the 45 deg tube from the air idle valve.

>    The guy had the car for a week and telephone me to say he could not 

> find

>

> anything wrong and that the idle was high but still within specifications

> when in "Drive".

> Adding there would be a charge but not the amount of actual time because 

> he

> could not find anything wrong.

>

>    When I went to collect the car he attached a meter to show the RPM in

> "Drive",his jaw dropped when I went to start the car and I refused to 

> run,he

>

> frantically checked fuel pumps,pressure and sparks with no luck it all

> looked good

>    .I said I would leave the car and despite his embarrassment I was glad

> it happened there and not again on the road.He phoned me a day later 

> saying

> that he had spent a lot of time to discover that the E.H.A had gone

> intermittent and that it was going to get me home but required changing.I

> have now fitted a new one and hopefully,fingers crossed the curse of being

> stranded miles from home will be a thing of the past.

>    The first time it happened I had a small fuel leak on one of the pumps

> so a fitted two new ones plus a filter,it would not run and I could hear

> bubbles in the tank when the pumps were running so I clamped off the fuel

> accumulator,and I had bridged the pins on the fuel pump relay,it then ran 

> so

>

> in went a new accumulator and it ran but when the f/p relay was put back 

> it

> refused to run so in with a new fuel pump relay and it purred like a 

> kitten

> for 3 months and then died in a small town a long way from home.Needless 

> to

> say the tow truck driver cheered me up no end by telling how many "Benz's"

> he had hoisted on the back of his truck and raving on about how

> reliable"Toyota's"were.The next tow guy said more or less the same thing

> adding "if you weren't driving a "Toyota" you needed your head examined!

>    Truth is if we were all driving super reliable cars,well barring

> accidents,these guys would be out of a job.

>

>

>

>

>                Kind Regards  Dan Gardner 1986 560 SEC euro (220kw)

>

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