Ok, so its not a piece of heavy iron, but it is old and is a diesel. I have tried all over and cant seem to get this little engine figured out. 1972 220D Mercedes car, its my dads and he is 80 and likes it. so I am trying to get it fixed for him. 615 engine.No turbo. I will try to give the quick story. Lots of miles on it. Been hot a few times. started to run poorly with burning a lot of oil. I took it apart and put new rings in it. Measured the bore and it was still good. It has super hard liners I am told. Everything looked good inside the engine. put it all back together. New injectors, and had the inline bosh pump redone at a good shop. it was badly worn. Now it starts good, idles good. if you hold the throttle open, half speed or so, it starts to really knock and puff grey/ black smoke after 5-10seconds. acts like it has air in the fuel. I have ran it with clear fuel line on pump inlet and no bubbles. when it returns to idle it misses and puffs for a short time than runs smooth again. kind of runs the same when I drive it. has runs good than will smoke and chug. I have checked the valve(has overhead cam) and pump timing a few times and they seam to be right on. it does have precombustion chambers. can they go bad or get plugged? It has 15psi of fuel pressure at the front of injector pump. that is measured between the lift pump and the injector pump inlet. Pump shop says that seams ok. I am at the end of my Ideas. maybe you guys can shed some light on this little engine. Thanks
Is that at idle, or when it's acting up? And what does it do under load? or is this still on a stand? If it holds the same pressure when it's sputtering then that's internal to the injection pump, no help from me.
One of your new injectors is boffo would be my guess, premature indieselation.
I have the engine in the car. the fuel pressure stays the same with in 2lbs under load, or at idle. I did find a little info on youtube last night, about the precombustion chambers going bad. will cause loud diesel knock and erratic running. I think when I get a chance to work on it again I will pull the injectors and have them tested and pull out the pre chambers and look at them.
I wonder if there's a timing advance that takes that long to work? I'd try adjusting the timing by ear to see if it runs smoother with the timing turned a little late. Otherwise take it to the pump shop and see what they think.
Hold the throttle half open when it starts knocking & crack lines open. Should be able to narrow it down. I have the om616 in a 82 240d.
Google> 220d injection pump.. lots of good diagnostics.. it looks as tho fuel quality is a big issue and leaking hand primers..
The 220D my father had ,I remember had a pneumatic governor with an air intake butterfly valve . I was only a little lad then ,but is that working and piped correctly ?