300D Dies under load

1982 300D.."300D Dies under load" I have isolated fuel: changed filters, removed fuel tank and had cleaned, screen in tank cleaned,purged system with cleaner (Diesel purge), replaced fuel lines, cylinder compression across board was 305+-5,glow plugs replaced, new monark injectors (bench tested: 2300,2200,2200,2200,2150)checked timing chain and valve job (cam lobes looked good), and removed exhaust. Fuel is going to each injector. Car runs rough at idle and dies when placed into gear. In fact, while idling (high rev's motor sounds good)and I turn on air car stalls. I cannot find my past posting December/January so I am reposting. The car is somewhat drivable (2 feet) and goes along O.K., but as soon as I begin a relative climb the cars power diminishes or if I have to slow to a stop it dies if I don't feather the throttle. A far cry from how the car ran before. The cars symtoms began immediately when my wife was driving home and the car would go no faster than 20 mph up the hill when it used to move 45-50 on the same grade. I am baffled? What's left the IP? How can I test or rule it in or out. Let me know if my problem is solvable? Matt Kirk

Forums

Diesel Engine Specific Aid

Chassis Model Number

W123

Most likely pump related

That does not mean it is the injection pump itself. Have you checked injection pump timing? Have you replaced the mechanical lift pump? It could possibly be a problem with the pump timing (advance) device that is driven by the timing chain. Refer to the 617 turbo diesel factory engine service manual for a complete description of its function, removal and replacement.

Kent, I replaced lift pump

Kent,

I replaced lift pump and the car idled which is a far cry from what was happening before. The engine would studder a bit at idle but would not die even as I reved the motor and would quickly back off the throttle. When I placed car into drive it did die under the load. I would restart and had to press down on the fuel pedal to get it started again. Once the car was idling again I messed with the screw at the tail of IP and the idle smoothed out; once again when I placed into gear it died. To start again I again had to pump the pedal to get the engine running. Should I be messing with that screw? Question? If I were to purchase and put an electronic fuel pump ahead of the IP and the car was able to go under load would that tell me the IP is the only problem/issue I am dealing with? It's an expensive test. What else could I do to beable to isolate the IP? Or Pump advance timing device to indicate my problem? Thank You, Matt

Other suggestions

I don't believe installing an electric pump will solve your problem. You have something else going on and it may be the IP itself. Do one more test if you have not done so already. Run the engine directly on diesel purge. This will bypass your entire fuel system and even clean the pump as you run the engine. If no improvement then suspect the injection pump. The timing device is a long shot as I have not seen those fail except when a chain has been lost. Find out where you can get your injection pump bench tested by a Bosch repair facility.

Kent, Just ran 2 cans of DP

Kent,

Just ran 2 cans of DP through the fuel system. The stangest thing happened the motor wouldn't stay at a steady idle and unfortunately died when I put it into gear. It idled with help at 1100 RPM's. Here's another thought, do you think I rebuilt my injectors at too much PSI?(2300/2150/2200/2200/2200 PSI ea). Maybe the IP needs to be advanced to compensate the injectors or just rebuilt the injectors again at 1800 to 1950 PSI? Adjusting the screw in the back of the IP, could that be cause for concern? Let me know what you think about all I've thrown at you here? In the mean time I'll be trying to locate a shop that can test the IP. Thank You, Matt

Kent, Could the vacum

Kent,

Could the vacum mechanism on the back of the injection pump cause the car to stale when placed into gear?

Matt