Need Help with OM606 NA, smoking like a train
 

Hey there everyone,

I'm posting on this forum after being a lurker for awhile, and need some help from the powers that be.

My car is a 1995 E300D, OM606 motor, non-turbo. 240K miles, and I'm in the middle of getting it back to life after the IP took a nose-dive.

I have replaced EVERYTHING in the fuel system, from the tank strainer up to the injectors, which I had digitally balanced, rebuilt and pop-tested with new Bosio nozzles by KermaTDI.

I just got done today with putting the IP back in, and reassembling the motor. I had to wait on the mercedes locking tool for the IP, its critical, and can't be gotten around.... (ask me how I know...)

Anyway, the motor fires up, but I have severe "chuffing" out of the tail pipe, and I think I can hear a slight nailing from one cylinder.

I'll attach video clips of my exhaust and engine, which has the ability to smoke out my garage in roughly 8 seconds right now, but is a LOT better than the last time not using the IP locking tool.

The issue seems to be an overfueling problem, which, starting tomorrow, I'm going to try and isolate to a given cylinder. The question, and the reason for this post, is what would make one cylinder overfuel? Timing?

The replacement IP is a mercedes re-man unit from the benz store in atlanta, and was supposedly bench-tested and checked out.

Any and all help is appreciated guys, if you want the full saga of this project, its over on another forum, and can be found here: 1995 E300d sudden power drop/no-start - Mercedes-Benz Forum

Youtube clips of motor and exhaust today after reassembly are here:

Motor - http://youtu.be/NTJ9L4nvqaw

Exhaust - http://youtu.be/Rk2dwTGCPkY

Thanks in advance for your help!!

- OTM

Hole in piston?

Pull oil cap... does it puff also?

How did it run before you did the work on it ?

Ran fine, apart from abrupt stall when IP gave out - bearings and metal shards all over when I pulled back plate...about 3 days prior to IP death I noticed a little white smoke in the mornings, but no coolant smell, and started right up.

No smoke from oil cap.

motor has plenty of power now that IP is replaced and catalyst replaced.

If you determine that it is a single cylinder:

A single cylinder problem has to be isolated to that cylinder.

The injector. Try moving it and see if the problem moves with it.

The IP piston for that cylinder.

The cylinder's piston rings, piston, cylinder wall, valves. If everything was fine before, it would not likely be those.

How is the IP piston for each cylinder serviced? Is that the piston under the delivery valve body? Is that somehow adjustable, and thus, responsible for the overfueling of that cylinder?

If I get it isolated I'll swap injectors - good idea, thank you! Kerma did a really nice job on them, but I'm sure there has been ample time for some nasty bits to slip in there during all this work.

Is the engine warm when you recorded the tail pipe video?

yes at 85~ degrees C after a short highway drive. I took it out to run it and see if that would make any difference.

Do you know what the pop pressures for the injectors were set at?

I do not have pop pressure figures. I do know that Kerma sent them to their injector shop, and they were all balanced and digitally calibrated within 0.5psi of each other.

Loosen fuel lines to kill the injectors one at a time. If you can turn the problem off this way, the problem is an injector, or the fuel delivery to it.

Looks to me like the offending cylinder is being starved for air.

the Cam followers are known to fail if bad oil pressure, or foreign materials come to play.

pull your cam cover, and look for wear on one of the cams, or a follower (I'm not sure how the 606 handles cam/valve duties...)

I had one do something real similar one time after performing a delivery valve seal job. Seems I had boogered up the "pin" that kept the cylinder in line. Took it to an injector shop where they were able to fix it without a lot of expense.

Ok ladies and gents. Got some progress.

The problem lies with cylinder #1, which is the one closest to the radiator.

I've swapped injectors, and that's not the issue.

The engine runs well and exhaust is clear if I crack injection nut.

I went back and pulled delivery valve body, cleaned, and re-torqued to spec. No change.

I can see into prechamber a little with flashlight, it's sooty.

Valves are cleaned with CCC. They're not bright shiny metal but look pretty good and do not appear to be sticking as I rotate engine.

So what the hell is next? Is this another IP problem? Do I check compression? Is there a way to pop delivery valve and check if something is boogered in that?

My prechamber set from pelican isn't here yet, because they are awesome apparently, but would a cracked or otherwise compromised prechamber do this?