[W126 Coupe] no fuel flow

[Dick Spellman]

Gotcha.  Not sure what to suggest.  All you've got are two pumps a check 
valve in line (that's at the metal line at the pumps), the 
damper(accumulator) and the fuel supply plus return lines up front.

If the system were buttoned up and you had a block in the return line 
you would have no fuel.  But, you are saying both lines are open up in 
the engine bay.  So, sounds like the problem is in the fuel pumps or you 
have a pinched (like in closed) fuel line on the supply side? How about 
placing a short line off the supply side at the pumps and testing from 
there.  That would tell you if the line to the engine is damaged.  Also, 
how long are you leaving that jumper in place and is it 14ga or better?

Can't offer much else. Good luck.

Dick

Markus Meyer wrote:

> Hi Dick,

>  

> I think you misread, or I didn't communicate well.  The "toasted 

> engine" is outta there.  I put in another motor from KNOWN GOOD CAR 

> that ran fine!  I do NOT have the lines hooked up to the engine yet, I 

> am simply testing that fuel gets FROM the tank TO the fuel 

> distributor.  The supply line coming from the tank to the distributor 

> is hooked into a bottle for now.  I thought the accumulator in the 

> back by the pumps/filter is for warm starts.  I thought running the 

> pumps in constant on should cause fuel to flow.  I am NOT trying to 

> check starting the car yet, that's the next step.  I wanted to make 

> sure fuel was flowing first, since the car itself was an unknown, but 

> the engine is not.  Make sense?  So I am not trying to test pressures 

> or any of that.  I am just trying to make sure fuel flows from pump to 

> fuel distributor, which right now, it is not.

>

> Markus Meyer

> mfm at meyerprobateproperties.com 

> <mailto:mfm at meyerprobatepropertie%0A%20s.com>

> www.meyerprobateproperties.com <http://www.meyerprobateproperties.com/>

> Meyer Probate & Properties, LLC

> 484-919-9762

>

>

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

>     Subject: Re: [W126 Coupe] no fuel flow

>     From: Dick Spellman <spell.yy at verizon.net>

>     Date: Fri, January 11, 2008 7:29 pm

>     To: Mercedes Coupes Mailing Lists <mbcoupes at mbcoupes.com>

>

>     Hi Markus,

>

>     Flow. You have a fuel regulator on the supply line before

>     connecting to

>     the fuel distributor. That's where I'd test for fuel flow. Also the

>     return line and damper can be checked which if blocked would restrict

>     flow on the supply too. Disconnecting at the fuel regulator will tell

>     you if you have fuel.

>

>     Markus you need a set of gauges for most the pressure tests. Read

>     07.3-120 and follow the steps. Given that the engine may have had

>     excess fuel dumped in there I be sure check the pressures & cold

>     start

>     valve plus temp switch that drives this valve and hope the engine

>     is not

>     toast from r aw fuel mixing with the oil.

>

>     Dick

>     not a mech, just a diy'r remember

>

>     Markus Meyer wrote:

>     > I have an 89 560SEL I just finished transplanting an engine and

>     trans

>     > into. I know the motor is good, it came from a good working car. As

>     > a quick test, I wanted to verify I had fuel coming out of the fuel

>     > line going into the fuel distributor. That line is what I stuck

>     into

>     > a bottle to do the test. Then, I jumpered pins 7&8 on the fuel pump

>     > relay, and no fuel.

>     >

>     > I tested voltage at each of the pumps (there are 2) and each read

>     > about 10.5 volts. I also tested continuity on each pump, both read

>     > about 2 ohms. I can hear both pumps "buzzing/humming". I know

>     > there's gas in the tank for two reasons - I added about 2-3

>     gallons,

>     > and just to make sure it made it to the first pump, I pulled the

>     hose

>     > from the tank to the pump off and fuel poured out. Also, when I

>     got < BR>> the car, I was told the engine might be bad because

>     "too much fuel"

>     > was dumping into the engine, so I know there was flow at one point!

>     > ;

>     > There doesn't seem to be an easy way to remove the "out" on each

>     pump

>     > one by one to test flow, considering the out on each pump is

>     where the

>     > wiring connections are, and I don't want fuel to pour onto the

>     live wires!

>     >

>     > So what can I check/test? What could be the problem? I should be

>     > getting fuel flow by doing this test, right? What the heck am I

>     missing?

>     >

>     >

>     > Markus Meyer

>     > mfm at meyerprobateproperties.com <#Compose>

>     <mailto:mfm at meyerprobateproperties.com <#Compose>>

>     > www.meyerprobateproperties.com

>     <http://www.meyerpro%0A%20bateproperties.com/>

>     <http://www.meyerprobateproperties.com/>

>     > Meyer Probate & Properties, LLC

>     > 484-919-9762

>     >

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