OM617 Injection Pump Timing Question - Page 2 - PeachParts Mercedes-Benz Forum

Diesel911 · #16 09-16-2018, 10:45 PM

Quote:

Originally Posted by BenzMacX

Thanks for all the help guys! Sorry my posts my be a bit out of order...

Diesel911 - This is more or less the same thing I am doing. Throttle is zip-tied wide open near the IP, shut off valve is disconnected.

The only difference is that I used an external fuel tank with a hand pump to maintain ~4psi fuel pressure. It just seemed like a more consistent method in my head. This is the way the ************** guy does it. *edit* apparently his name is a curse word here?? Did I make a mistake following his direction?

I have not made any adjustments yet, its dripping as it should at about 24-25degrees BTDC. The only thing I have heard is that an older engine might benefit from some sight advance(26-27 degrees BTDC), but I haven't decided if thats the route I want to take. Id rather make sure everything else is looking good.

Jim

At the Fuel Injection Shop I worked in we had a gravity feed setup. So we always got an even flow.

But, if you rotate the pump and then snug one Nut down so that working the Handprimer does not rotate the pump you will get an even pressure while you pump because of the Fuel Pressure Relief/Overflow Valve. You just count the drops while you are still pumping.

If at about the level of your Lift Pump you have a plug that would use a 17mm wrench on it. You have the access port that can use the Timing Locking Pin which is arount $37. It is mainly used to keep the fuel injection pump from rotating when after having removed the Fuel Injection Pump you re-install it but it can be used for retiming. (Using the Locking Pin the timing on my year and model is 15 degrees after top dead center right after TDC of the compression stroke.)
If you want to take a look at one Pelican sells them and there is a bunch of treads where I have posted picturs.

Did you mention what color the smoke is?

Another item that can cause smoke is sticking piston rings. I had that happen to my Volvo Diesel (I had hazy gray smoke all of the time) after it sat for 1.5 years in my back yard. In my case I used Marvel Mystery Oil dumped through the Glow Plug Holes and let it remain there for 2 weeks and rotated the Engine and dumped more in but only got to wait another week before I had to get it on the road. People have used other stuff to do the soaking.

A few people have had leaky valve stem seals. I changed the ones on mine and noticed no difference but it has worked for others in the past.

People claim if the little O-ring on the Fuel Supply/Lift Pump goes bad it sucks Oil out of the Fuel Injection Pump and it eventually gets injected into the Engine.

If you remove one Injector and the Heat Shield and peer down inside and you see a lot of shiny wet looking carbon that is Oil getting into the Per-combustion chamber and burning. When you look in there it ought to be flag black with a light coating of carbon.

Result of me advancing the timing to 28 degrees
http://www.peachparts.com/shopforum/showthread.php?t=248979

Attatched pic of a gravity feed setup. The one we had was different as we used it on a variety of different pumps.\
Some people don't like me posting the next picture. If you rotate the Engine in the direction of rotation and extremely carefully line up the marks on the Cam Gear Wsher and the front Camshaft Bearing Tower and look down at the Crankshaft Damper degree marks you can get an aproximate idea of how much of your camshaft timing is due to timing chain stretch and or timing gear wear.

BenzMacX · #17 11-05-2018, 11:46 PM

Sorry for the delay in responding.

So the smoke is black. I do not see any hint of blue and it is certainly not gray or white. Which would indicate to me that this is a fueling issue, correct me if I am wrong.

I replaced the injectors a while ago, unfortunately I did not checkout the pre-chamber all that closely. I may have a go at pulling them again, just need to get the crush washers.

After checking the timing, the delivery valve was leaking and I noticed that the o-rings (which I assume is just to keep crap out) was basically useless. So I ordered new crush washers and o-rings for the delivery valves. While I was in there I took a closer look around and just noticed something rather odd looking about the pistons in the IP. They all looked almost exactly the same, but it just didn't look like a nice cleanly machined part that I would have expected... Basically the top of all the pistons in the IP has a notch/cut out that just didn't look very clean. Took some pictures, let me know what you think

Not too sure where to go from here... Pulling the injectors to inspect the pre-chamber and dump some mystery in seems like as good a place to go as any.

Also If I didn't mention it earlier, I adjusted the timing back to about 26 degrees, looking at the smoke from the mirror while driving, it does not appear as though anything has changed. I may bring it in for an inspection just to get a baseline, but they aren't exactly cheap out here, $80+ each time last I went.

Pictures are here: https://imgur.com/a/2VQ9hIF