190D 5-speed, jerking and bucking between 1500-2000 RPM - Page 2 - PeachParts Mercedes-Benz Forum

PKdavidson · #16 02-11-2019, 06:37 PM

Quote:

Originally Posted by Maxbumpo

I think there is supposed to be a little shock absorber on the injection pump linkage, is that missing? Dead and not effective? I've owned both a 123 with a five speed and a 1984 190D 2.2 with a five speed, and they both had the little shock. The purpose is to prevent a harmonic disorder between the engine and the IP linkage. When that little shock on my '84 190D died, I had the exact condition you describe.

I think you may be on to something. It looks like the little shock absorber is missing. See attached photos.

Does it link up to the ball joint on the intake runner itself above or somewhere else? Just ordered one from the UK. Part number doesn't seem to be available at any US online store.

190D 5-speed, jerking and bucking between 1500-2000 RPM-img_5549.jpg

190D 5-speed, jerking and bucking between 1500-2000 RPM-img_5550.jpg

Maxbumpo · #17 02-12-2019, 05:07 PM

Quote:

Originally Posted by PKdavidson

Is this what you're talking about? #143?

That's it!

Maxbumpo · #18 02-12-2019, 05:09 PM

Quote:

Originally Posted by PKdavidson

Does it link up to the ball joint on the intake runner itself above or somewhere else?

It attaches on the intake runner, I can see the little ball in both pix. That's the fixed end, the other end attaches to the moving part of the linkage.

PKdavidson · #19 02-19-2019, 10:36 AM

Quote:

Originally Posted by Maxbumpo

It attaches on the intake runner, I can see the little ball in both pix. That's the fixed end, the other end attaches to the moving part of the linkage.

Just got the part in and got it installed. Had to get creative with angles to get it to snap on the linkage. Harbor Freight long angled pliers for the win!

It helps the bucking a ton. It's not completely gone but it is a lot easier to deal with especially in traffic where I couldn't avoid it. Thank you for the tip. Also smooths out my starts a lot now that the throttle is a lot heavier than it was.

It wasn't an easy part to find. Had to get one from Spareto which then shipped from Estonia.

Again, thank you! Best lead I've received on the issue.

vstech · #20 02-19-2019, 05:26 PM

Odd bucking issue.
Where did you get everything that was replaced, and what brand parts went in?
I'm skeptical of the motor mount change, the injector replacement, and the pressure plate...
The clutch disk has springs in it to absorb rpm as you change gears. Weak disc springs could cause bucking if not tuned for the 2.5 diesel torque curves...

PKdavidson · #21 02-21-2019, 09:45 AM

Quote:

Originally Posted by vstech

Odd bucking issue.
Where did you get everything that was replaced, and what brand parts went in?
I'm skeptical of the motor mount change, the injector replacement, and the pressure plate...
The clutch disk has springs in it to absorb rpm as you change gears. Weak disc springs could cause bucking if not tuned for the 2.5 diesel torque curves...

The previous owner did most of these parts. I have the old ones in the replacement boxes. And it appears under inspection that my motor mounts are the wrong part number. The ones I have are 1242401717, Febi 03428 - these are for the automatic transmission. The box and receipt confirms.

The ones I need are 1242401617.

I don't know what the differences are between the motor mounts. Do you think this could cause the bucking issue? It's worst when accelerating from low RPM in a higher gear.

The clutch kit is a Sachs and is the correct part number.