Okay, first of all, I have been searching and trying to find someone with my problem but I haven't.


I bought a 95 E300D about a month ago, I've been going through the car and figuring out what to replace as I go. I'm on to injector nailing while I wait for the new radiator I ordered to show up, after I replaced the original vacuum pump with 260k miles on it and all the plastic fuel lines.


Anyhow, let me describe my symptoms and what I've done so far.


When I first bought the car it would nail from idle (~550 RPM) up to about 1,500 RPM. I ran the tank low and put two cans of diesel purge (DP) into it and the nailing got a little better. Now it nails from about 700 RPM to about 1,100 RPM. I still plan to run the engine on only DP when I get back from my grandmother's celebration of life in Michigan... ANYWAY... So, usually, when I start the car cold it starts right up idles fine for about 5-10 seconds (I imagine right about when the GPs turn off) and then the nailing starts. It will nail at idle until it warms up and then the nailing at idle goes away and behaves as I described earlier (700-1.1K). Occasionally, I will come out in the morning and start the engine, cranks over and starts right up then the glow plugs will kick off and it will have a miss on one cylinder and ***** smoke for about three to ten seconds. I will usually give it a bit of throttle (~1,800 RPM) since that absolves the nailing I figure it will help the combustion. It almost seems like one injector will get stuck open for a couple seconds. Any input or recommendations would be super awesome. I pulled the valve cover cover off and listened to each injector with a stethoscope but they all sound about the same to me.



Thanks for reading!

I am assuming this is the vehicle milage; 260k.

Somewhere between 125-150K it is possible for the Fuel Injectors to start having wear and to low of pop pressure issues. I if the injectors have never been rebuilt at 260k miles that the nozzles are worn out and the pop pressure is low. The low pop pressure effects the timing.

That being said low compression and Timing Chain Stretch can get your Fuel Injection Pump and valve timing to be late/retarded. The Fuel Injection pump can be re-timed on the Engine without messing with the timing chain but that of course won't change the valve timing.

Worn Injector Nozzles don't atomize and or don't spray where they are supposed to. When I got my Mercedes it had about 198K showing (I already had a pop tester and knew how to use it) and I found what must have been the original Injector Nozzles were all worn out.

You could pic one of 2 Injectors and take them to a Fuel Injection Shop and see if they would do a free pop test on them. I don't know about know but in the past they used to do that.

In the mean time a fuel additive like Diesel911 you can get at Walmart has a higher cetane rating and will I think at least reduce some of the nailing.

__________________
84 300D, 82 Volvo 244Gl Diesel

If you do the below make sure the Fuel Injection Pump Flange Nuts/bolts are loose before turning the adjusting screw. Also I don't know if there is another support at the rear of the Fuel Injection Pump. If there is that would also have to be loosened.

If your Fuel Injection Pump has the screw on the side to change the Fuel Injection Pump timing if you have a mark on the Block to Fuel Injection Pump Flange or you put your own mark it is possible to loosen the the Fuel Injection Pump Flange Nuts/Bolts and use the adjusting screw (don't do this with the Engine running) to advance the Fuel Injection Pump timing just a bit.
Only rotate the pump a tiny bit. Noting the marks and or your own reference marks allows you to return it to where it was when you started.

There is supposed to be an O-ring sealing the Pump to Block area. I don't know if rotating the pump a bit would cause a leak or not.

__________________
84 300D, 82 Volvo 244Gl Diesel

Thanks for the tips!

I'm worried it could be a number of things all contributing to the issue. I've read that bad lifters can cause nailing due to low intake volume at lower RPMs. I'm going to get a pop tester and start with the simple things first. My nozzles likely are worn and replacing them will likely make things better. I'm just worried this car is going to try and bleed me dry

Well yeah that is always a possibility with a car of this era.

I would recommend pulling the injectors and either reworking them yourself or look up forum member Greazzer, many on here have used his services and he does a great job for a reasonable cost.

While you have the injectors off, do a little PM on this engine and replace the following things:
- valve cover gasket (the main one that goes all the way around)
- Injector well seals (there is one at the top and at the bottom of each well, pull up on the funnel to get the bottom one, very easy to do when the injectors are out and you have the valve cover off)
- Be sure all your hard line clips and spacers are there. The rubber spacer pads dry out and fail and this causes the lines to vibrate and fatigue crack.
- You already did the low pressure fuel lines, that’s good. Don’t forget about the rubber lines going between the engine and the body.
- Glow plugs are a thing with this engine, they have a nasty habit of getting carbon packed (particularly if you have an injector issue) and can snap off in the head as you try to remove them. The plugs are very long and slender to get the business end down where it needs to be with the DOHC arrangement. There are tooling kits available to drill out broken plugs. I have the kit from my OM606 days and will loan it to forum members.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech