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6.3

Rich running
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I guess I missed that part. It’s likely a sealant. I have only used a metal sealing washer. The pumps I have gotten back from rebuilding did not have any sealer either.


Jim
I was looking through the workshop manual to service the temperature control/sensor on top of the injection pump and it says to apply ‘Starrit" to the heat sensor before closing, can some one tell me what is starrit.  Thanks in advance.
I have changed the MFI pump oil and the engine oil and filter, the pump I kept as Mobil 1, the engine oil I changed to Penrite HPR 40.
I then removed the thermo device from its hoses and started to clean it out, it was full of junk. I clamped the garden hose to the inlet and let it rip, the wax thermostat came out with a cup full of crap!
After scrubbing everything clean and checking the wax thermostat in boiling water then cold water for response, which was evident. I reinstalled the thermo device and warmed her up.
At about 125 on the temp gauge the idle began to drop below what I have been able to get it to and 2 and a half turns out on the air idle screw had it back to 550-600 RPM and very smooth.
I haven't rechecked the timing yet.
All warmed up I went for a quick test drive that became very quick indeed, she performed beautifully, just a wisp af grey smoke until over 175 on the temp then none I could see while I was watching the end of the road looming very fast.
Seems the thermo device cleanout has done the trick!

6.3 #2723, my first classic Benz
Don't assume the level stays correct,as it leaks fuel in from the plunger gallery.

...There are old cars,and then there are Classics..(Mercedes Benz Ad. 1999)
I have Mobile 1 in the rear of the pump, measured in at 250ml as per your earlier advise, I sucked out all the old oil first. I changed the engine oil and filter at the same time with Mobil 1 and a MB filter.

6.3 #2723, my first classic Benz
Yes very good.It's good you are not afraid of tackling the Wax stat in the thermo device.You can lengthen the rod to the throttle body a few millimeters to stop stalling.It's not really reccomended but it seems to work occasionally.
Hows the oil level in the rear of the injection pump? ,a good idea to suck out as much of the old oil as you can,then replace it with (approx) 200mls.I understand Mobil one is good choice as it's not readily affected by Fuel contamination.

...There are old cars,and then there are Classics..(Mercedes Benz Ad. 1999)
I have removed the 7mm bolts from the the back of the cold start valves as described and have no fuel at all out of them with the ignition on for 20-40 seconds, engine cold, so can i assume them ok?

6.3 #2723, my first classic Benz
I've cleaned out the piston in the thermo device, it was not stuck but sticky, not smooth, and set the screw adjuster at the top of the piston as high as I can to lean it out a bit, the smoke has reduced to just visable and the response is very crisp. I got to that by winding the screw right in, way rich, then right out, would idle but stall on throttle, setting it 2.5 turns out from the origional setting is where I'm at now (about 1/3 out from the piston base) Tomorrows job is the cold start valves.

6.3 #2723, my first classic Benz
Anyone have the bunnies email address...

6.3 #2723, my first classic Benz



1971 Mercedes Benz 250CE (RHD in the UK)
1973 Mercedes Benz 280SEL 4.5
1979 Mercedes Benz 450SEL 6.9
1997 Mercedes Benz E420
A couple of easy steps before you adjust the mixture: Turn the ignition switch on. Remove the tiny 7mm closing plug on the cold start valve (one at a time). If there is a great quantity of fuel coming out, no adjustment of the pump is going to help. Time to re-kit the valve(s). Second, remove the 2 screws that secure the choke thermostat housing to the lower piston section of the choke assembly. Be sure there isn't pressure in the cooling system and use a rag for coolant residue. Lift the thermo housing with the choke thermostat slightly to the side (hoses attached) and using a drift or substitute apply downward pressure to the piston of the choke housing. It needs to move freely with spring tension(as this governs air/fuel ratio upon warm-up and as the base setting for warm run). Remove the piston and clean if it is frozen or sticks. You can also test the operation and adjustment of the choke thermostat by removing the small air filter of the inlet pipe. With engine running cold, it should pull a vacuum -after warm-up the thermostat extends and closes the piston oriface (no vacuum). Good luck, Michael.
Now I think about it I ran a cooling system cleaner through a few weeks ago, could a bit of crap get stuck in the thermo device?

6.3 #2723, my first classic Benz
Thanks Ron, I suspect the pump is the problem also, my cold start relay is wired to a button under the dash that clicks the relay in on starting

6.3 #2723, my first classic Benz
WELCOME TO THE WORLD OF 6.3 PAIN....[}:)]
Rich running is caused in Short by a worn Injection pump.Art has had his 600 pump rebuilt for reasonable price in Melbourne,certainly a lot cheaper than the equivalent Toyota Diesel pump.
You can check your cold start mechanism to ensure it's working OK.
Quick checks can be done by feeling the two rubber hoses comming from the top of the injection pump,when the temp guage reads warm,they must be hot,indicating that water is circulating through the thermo device.
Next,the cold start injectors can be checked for leaks( inside the manifold) by looking at the back of the manifold and you will see the cold strart valaves.there is a 10mm bolt ,undo this and turn on the igniton,there must not be any drips of fuel.

Thats about all you can safely check for...Waer seems to be around the govenor mech.in the back of the pump so theres not much show of adjusting it out.[xx(]


...There are old cars,and then there are Classics..(Mercedes Benz Ad. 1999)
I have #2723 running well, but it is as rich as, how do I lean out the injection pump without mucking everthing up?

6.3 #2723, my first classic Benz
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