[W126 Coupe] Hard Start Problem

[Dick Spellman]

Hi Henry,

Fuel filters (messy affairs) are behind passenger rear wheel.  Don't forget
to order the 2 new crush washers needed for each filter.  They do not come
with the filters.  Accumulator is right up there with fuel filters and
pumps.  Best to test fuel system with a fuel pressure gauge hooked up to the
fuel distributor upper and lower chambers.  (I have a write-up somewhere
with photos or maybe even up on Steve Nervig's pages, not sure)  With
gauges, you know exactly where leaks and or troubles are on the fuel
system..  You don't want to guess as it just costs lots of time and money if
you throw parts at the problem.

O2 if 80-100k no doubt, just replace using the Bosch (Mustang) 3-wire
version and solder/tape).  Also, the fuel distributor control piston seal
will leak with age.  I wrote up how-to on this some time back.  If you see
that it's leaking then order both the piston seal and then the fuel
distributor base seal too.

That guage set-up will point out all leaks including injectors so that's the
way to go.  If you need a link to the supplier for a set-up made for your
MB, let me know.  They are about $80.

I'd check over the cap, rotor, ignition wires too.  Maybe run the motor at
night, 'look' for any arcing on first the coil wire.  Generally wire set
needs replacement at 100k too.

Set-up a vacuum gauge on the manifold to see if any leaks are obvious.  All
of the above should get that motor running smooth and starting right once
again

Good luck,
Dick

On Fri, Dec 5, 2008 at 10:52 AM, Henry Viveiros <henryviv at grantspass.net>wrote:


>  The problem does not happen on my first start of the day. It only happens

> after I have parked for a short while and then try to start again.

>

> I'll change the fuel filters (wherever they might be). They've been on for

> more than 5 years. Could the O2 sensor for the catalytic converter cause

> something like that? That hasn't been changed either. I'll also try to

> determine where the fuel accumulator is.

>

> My wife has a 1986 560 SEC so I may be able to swap parts instead of

> blindly buying parts. I really don't know what I'm doing but would rather

> play with things than take the car to the dealership in Medford (about 30

> miles away from Grants Pass, OR).

>

> The MB Coupes Website!

> W126 SEC Mailing List

> Postings remain property of MB Coupes, L.L.C.

>

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