Topic: OM617 engine shutter after revving at idle

[Alec300SD]

We all make mistakes some times (filling the engine with oil with the drain plug out, etc.)
Worst case scenario with the PRV in the incorrect position could be a minor loss of some power/responsiveness.

If worn excessively (or out of adjustment) the rack damper bolt can definitely affect the return to idle adversely.

Most likely culprits affecting engine performance at warm up are air ingress, clogged fuel filters, low cetane fuel, water in fuel, dirty fuel tank/fuel strainer, tight valves, poor injector spray pattern, glow plug failure, and a dirty air filter...just to name a few.

I'd address those areas before looking at the rack damper bolt.

The diesels respond well to being driven spiritedly on a regular basis.

[OLDGOLD]

OK, I replaced the rack dampener bolt last year, but I'm not sure if it was adjusted correctly.

I just replaced all the fuel filters last week, the air filter a few months ago, had a valve adjustment less than a year/5k miles ago, new Monark nozzles less than 6 months ago and I use Shell V-Power Diesel with TK-7 additive (w/ cetane booster) only at every fueling. I haven't check the fuel screen, but I will eventually replace that as well.

I'll try adjusting the RDB soon and let you know what happens.

Thanks!

[OLDGOLD]

I just realized something when watching a MS video on YT. I noticed that when he was revving up a 240D from the linkages by hand, how smoothly it settled back to idle with not even a hint of a stumble. (https://www.youtube.com/watch?v=uO_QO2lPbWU&list=PLtRKk64pu2wpQBZU9mSxKU2Wb-iSabXIT&index=6 at the 2:39 mark) I saw that when he released the linkages, they smoothly went back into their resting position almost like fancy soft-close kitchen cabinets. I do know that the linkages changed from chassis to chassis or from year to year, but could the linkages be causing the engine to rev lower than it should when rebased back?

My fuel system is in top notch condition with a recent purge, monarch nozzles, new fuel filters with Hebmuller primary and Mann secondary, new lines and primer pump as well. There has to be something causing the strong stumble on return to idle. Please help!

[Squiggle Dog]

My roommate's 1991 W126 350SDL does this! When the accelerator pedal is let off, the linkages slam down and push against the injection in the opposite direction and about shuts off the engine. Taking the slack out of the linkage seems like it might have helped a little, but didn't solve it. There may be a spring missing.

[OLDGOLD]

Does your 300SD have a linkage spring?

[Squiggle Dog]

Does your 300SD have a linkage spring?

I looked and didn't see one on mine, just the one at the accelerator pedal on the cabin side of the firewall.