[W124] RE: [Mercedes] Intermittent Starting Problem

[Stadter, Jim]

Paul wrote:
> On my '93 320CE, I often get a no start situation, other times it's fine...
> Symptoms are that starter will spin normally, but no fire whatsoever. I've
> tried pushing the accelerator to the floor (in case it was flooded), but no
> luck. Try say a dozen times and give up before I flatten the battery. Come
> back 1/2 hour later, it starts first time (but sometimes doesn't)
> The temperature (of the weather, or the engine ) seemingly doesn't make any
> difference, it's the same cliff-hanger hot or cold......
> Hope I'm describing something that has happened to other members and they
> have found a cure ?
> If not, I guess I'll have to start a thorough diagnosis the hard way.....

Paul,

  This was recently posted on another list and sounds like it may be applicable.

Jim
'89 190E 2.6  217Kmi
'94 E500
Austin, TX

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Hi All

We have an 1980 TE280 which displays an irritating hot start problem.

When cold the motor cranks over and fires on the 3rd rotation, everyone
is happy!

However when the motor has warmed up to operating temp, the motor needs
to turn over 10
to 30 times before it fires.... This is especially true if you leave
the warm motor for 10/15
minutes before the restart attempt.

I am replacing the fuel filter today, to ensure the feed line is
unrestricted.

I have not checked fuel pressure or any of the thermo timers, as yet.

Hopefully wishing someone has that edition of the Star magazine that
mentioned this
problem, and I cant find, or is aware of the issue....


Thanks.

Message: 1
Date: Mon, 8 May 2006 18:44:42 -0400
Subject: Re: [Mercedes] Hot Start Problem W123/M110

We had a similar problem on a 78 450 SEL that I corrected by adding a
switch that I could activate the cold-start valve with.  The switch was
wired so that it could only be activated when the ignition switch was
in the start position.  There is an old tech note somewhere with the
details.  Bottom line is that when the engine is cold all is well.  If
the engine has been off for only a couple of minutes, all is well, if
the engine has been off for more than as few minutes, but not long
enough to actually get cool again, then it has a restart problem.  The
tech note said that the problem was related to vapor lock and that is
why activating the cold-start valve (which supplies fuel and chokes the
engine) works.

BTW, all I did was to mount a small horn-type button high up on the
left foot rest.  All it did is provide a ground to the cold-start valve
(which opens the valve only when the ignition switch is in the start
position).  When the car had problems starting, I pushed on the switch
while starting -- It always worked.

Good luck.

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