Hi

New to the forum. Hi!

1986 300SDL. 225k. 10k on rebuilt motor (mercedes indep). I received car after my dad passed away a few years ago. I used to drive him to drs appointments, etc. Long wheel base & my dad was a tall guy (6-5) so plenty of leg room in rear.

Car has been parked in driveway for about year. Fairly good slope to driveway. I start and run in park every week or so. Non-oped so hasn't been on road.

I took it off non-op month ago. Driving to gas station, very little power. Barely got back to house, and prob ran out of gas as I got into driveway.

Put about 5 gallons diesel in, at home. Started one time and then subsequently wouldn't start. Cranks fine, runs for a second and stops. Eventually does not run at all. Gage shows 1/4 tank. I suspect fuel delivery.

Additional: Glow light does not come on, but not sure I recall light in past.

Read the forum. Tried a few things.

Pre-filter is not clogged - can blow through. Loosened all bolts for spin on filter one at a time - when cranking, no fuel.

Tested glow relay - batt voltage on bus both sides. Each contact to glow plug reads 1 ohm except one shows 22 ohms. All 6 pins on relay show batt voltage.

If one plug is marginal, bad, should still start?

 

No replies

I'm thinking, removing the fuel pump connected with the gas tank. It should be possible to test outside of the system? That would be next step if that seems reasonable.

Almost no fuel coming out pre-filter - even if you remove the filter from the supply

Any thoughts?

 

I am having trouble organizing My thoughts to day so some of the below may come out disorganized.

I am not sure I am misunderstanding you; no Fuel Pump in the Gas Tank like there is on Gasoline Cars.

The Fuel Supply/Lift Pump is on the side if the Fuel Injection Pump. It is a Mechanical Pump that runs off a lobe of the Camshaft inside of the Fuel Injection Pump.
Because it is a Mechanical Pump it is easier to test it while still on the Fuel Injection Pump.

It could be that the Fuel Tank Screen at the bottom of the Tank is plugged.

You might try by passing the Fuel Tank and getting a can of Clean Diesel Fuel and running a separate Hose to that and the Fuel Supply/Lift Pump and see if you can get the Fuel Supply/Lift Pump to suck and push out the Fuel as a way to test it.

In your particular Fuel Supply System there is no Hand Primer Pump like there is on the older Models.
Where the Fuel Return Line comes out of the Fuel Injection Pump there is a Fuel Pressure Relief/Overflow Valve built into the Bolt that holds the line on (Banjo Bolt).

So the Fuel Supply/Lift Pumps have disc Valves that don't seem to hold up as long as the Older Fuel Supply Pumps do. There is a Kit to rebuild it but it requires you to file off or grind the Crip off one of the parts.
Some have said the Fuel Pressure Relief/Over Flow Valves have a tiny Plastic Part inside that falls apart.
But, right now you need to know if you can get output from the Fuel Supply/Lift Pump.

There is a Vacuum shutoff on the Fuel Injection Pump and another Vacuum Shutoff Valve on the Steering Colum Lock.
On the older Models the tubing for that is Brown or Brown with a strip. Disconnect the Vacuum Line down at the Fuel Injection Pump and Plug it off. If you can start after that you have a problem with the Vacuum System.

If you verify you are getting output from the Fuel Supply/Lift Pump; connect it up and loosen the Fuel Injection Line (tubing) Nuts at the Injectors and Crank the Engine and see if you are getting Fuel from there.
If you are getting Fuel to the Injectors tighten the Nuts and recharge the Battery. When the Battery is ready attempt to start.

If it won't start after that let us on the Forum know.