[W126 Coupe] fuel problrm

[Dick Spellman]

Hi Clay:

Sounds like the car is flooding out while sitting with engine off.  That 
is likely a leaky injector or control piston seal.

To do an overall fuel system check that will determine that a leak 
exists on one of the following: accumulator, one or more fuel injectors 
and the cold start injector, you need to do the following procedure:

    * put a set of gauges on the fuel distributor,
    * jumper the fuel pump relay for 30 seconds to obtain system and low
      chamber pressures (write these down)
    * should be something like 5.45 bar system and 4.95 bar low end
      giving you a differential of 0.50 to 0.45 bar
    * keep in mind that at this point you are only need to measure and
      record system pressure
    * then remove jumper and let her sit for 30 minutes with gauges
      still attached.
    * Look for a any change such as substantial pressure drop on system
      pressure and report back.
    * Once you provide the pressures, specific tests for accumulator and
      injectors can be applied to identify the component needing your
      attention.


As for the control piston seal, you can visually inspect the area 
directly below this hidden seal to determine if it's leaking.   Take a 
flash light aimed at the air metering plate to the hinge side and fully 
depress and hold this plate downward (motor off) and look to see if the 
hinge area turns shiny wet like over the course of about 5 seconds or 
less.  If so, replace that $0.65 seal plus the fuel distributor base seal.

I have some photos of the gauge hook-ups  and maybe one or two of the 
r&r on the control piston seal that I can place in a PowerPoint and 
convert to Adobe.

I also have a source for the gauges for around $80 last time I checked 
and they are an exact fit to the Bosch systems on our MB's.

Good luck,

Dick

clay wrote:

> Hi Guys, I'll try to make its short and simple.

> Had all new hoses and elect pumps and filter installed,was running 

> rich, leaned out starts on first try from950rpm down to 750 when it 

> was rich did the same. when you turn fof car and try to start again 

> perfect. Let it sit for 1-2 minutes try to start have to put pedal to 

> floor and idles same as before. Don't know if should lean out more or 

> could it be a Fuel acculator that went bad. When you go start after 

> sitting it almost wants to start but doesn't any you have to floor it 

> .Please give some insight. P.S. I notiched a small drain of 0.5 per 

> day while I was checking thing out.

> Pulling my hair out,

> Clay Moizo

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