So- a few weeks back I complained about an erratic, (only sometimes) rough, loping idle issue with my 300DT.

It's not the motor mounts, I'm also very sure it's not the rack-dampener bolt...

I did, however, replace the hand-primer pump to the upgraded Bosch unit- and it made the problem a little bit better...

But there's still, an occasional, hard nailing/coughing when stopped in Drive.

I'm thinking it's probably an injector- is this a big job?

I've been doing a lot of reading on Monark injectors/nozzles- these better than factory?

I appreciate everyone's insights...

Randy

Injectors are an easy DIY.


Injector + Heat shield + Nozzle, Prechamber + Collar and Nailing. LINK THREAD
Injector + Heat shield + Nozzle, Prechamber + Collar, and Nailing. LINK THREAD



Have a great day.

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I cannot post any pics as I killed my good computer. But, the Stock Nozzles are now made in India and so far as I have read they do not have the best rep for quaility control.
You can see the pics I have often posted in other threads that shows the Stock Nozzles have tiny holes drilled down the center of the Tip of the Pintel on the Spray Nozzles and are cross drilled up higher in the Nozzles with a larger Holes.
On my own Engine I found that both of those holes were entirely Plugged with Carbon and it was the same with most of the ones I have pulled at the Junk Yard.

So, besides the Made in India issue the stock Nozzles if not kept clean with Diesel Purges; I believe they are more likely to get clogged than the Monark or the Bosio Spray Nozzles.

The Monark Nozzles are Made In Germany and do not have the tiny drilled holes to get plugged up.

I would read some more threads there is a lot of info on them.

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84 300D, 82 Volvo 244Gl Diesel

I left something out the German Made Monark Nozzles cost less than the Indian Made Bosch Nozzles.
I have a set of the Monarks in my Mercedes and I also put them in my Volvo and I like them.

To make up for the India bashing I bought some 2 and 1-1/2 inch Round Die Holders (stocks) for threading (made in India) and they are perfect solid Steel; whay better than the made in China one that I was using previously that is made of Potmetal with screwed in Steel Handles.
I liked them well enought that I bought 2 more of the 2 inch ones.

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84 300D, 82 Volvo 244Gl Diesel

Thanks... looks like I have some more reading to do!

Oh, forgot to mention- I did run a diesel purge and did replace both the spin-on and the line filters...

I'm going to tackle the injectors next...

Thanks again!

what's your idle speed in park and in D when you're at a stop light?

steve a

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Steve A
92 W140 OM603
97 VW Jetta TDI
90 Passat variant TDI 6 speed MT
94 Chevy K1500 6.5TD
05 E320 CDI
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I'll never bash bosch (they made alot of the parts on our cars!) I bought two rebuilt injectors from a good CO.
run them for like 2000 miles pulled all six to pop test and rebuid them my self with monarch nozzels

the two "new ones" had a bad spray pattern and popped no where near close to each other

so i will say no matter what brand of nozzels always rebuild them and test for spray pattern and pressure (pop) test them yourself or have some one on here do it and send them to you

I aswell as many others here would be willing to this service after all we maybe the next owner of your car!!

The number-five injector has moisture towards the bottom- where it screws into the head...

Do you think this can be a big source of my problem?

Thanks guys...

Probably not.

If you ever had a Injector Fuel Return Hose leak there or oil from a leaking Valve cover Gasket either are a likely source of that moisture at the bottom as there is no way to wash it out ounce it seeps past the threads.

But, it also is not unknown for the Injector Nut to develop a Hair Line Crack and leak.

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84 300D, 82 Volvo 244Gl Diesel

For your thoughtful responses- I really appreciate them!

Might also want to check the valve clearances if never done to your knowledge. Just quickly checking with a feeler gauge for any that might be far too tight. Required periodic maintenance. Every fifteen K recommended.