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Garage => Mechanicals => Topic started by: Mergyver on 03 March 2019, 12:49 PM

Title: OM617 Injectors Should I test them or just replace them
Post by: Mergyver on 03 March 2019, 12:49 PM
Hey guys I am hoping for some advice.

I bought a 1979 300SD last year and have just recently put it on the road. the car had sat for approximately 8-10 years before I bought it. It has 93,000 miles on it.

Prior to putting it on the road I drained all the old diesel fuel, replaced filters and cleaned tank screen, ran a few cans of undiluted diesel purge through it, replaced engine mounts, adjusted valves, replaced oil and filters, replaced rotten fuel lines and resealed injectors, checked turbo and boost pressure, and a few gaskets to stop oil leaks.

While the car is running well I don't seem to get as much power as I thought there would be and I have an intermittent miss at idle (some times it idles rough most of the time it does not). I have run two tanks of fuel through it and I am getting about 25MPG for a mixture of city and highway(mostly city).

The fellow who originally purchased the car had the dealer install an extra fuel tank in it. The purpose of the tank was to allow him to drive from his home in the NYC area to his vacation home in St Petersburg FLA with out having to stop for fuel. Remember 1979 was the days of the fuel embargo and Odd/Even gas lines.

My goal this year is to attempt that trip and see if it is possible. Half the fun of owning these cars are the stories we purchase them with. If I can average around 30MPG on the highway I think I can do it.

So  here's the question; Should I bother testing 40 year old (93,000 miles) injectors that sat for around ten years? OR should I just  toss them and get a set of those Monarch injectors that Ken B raves about on his sight? Do new injectors need to be tested to make sure they are balanced? I just don't know if it is worth spending time and money on a tester.

I also am hoping the Monarchs help increase my MPG. What do you guys think? Anything else you think I should do like checking injector pump timing or adjusting ALDA?

As always your words of wisdom are appreciated.



Title: Re: OM617 Injectors Should I test them or just replace them
Post by: Alec300SD on 03 March 2019, 02:54 PM
Send your new nozzles and used injectors to Mark (forum member Greazzer) at https://dieselfuelinjector.guru/

He has rebuilt mutiple injector sets for me and  many others.
He does top notch work at a reasonable fee
Title: Re: OM617 Injectors Should I test them or just replace them
Post by: Harv on 03 March 2019, 03:01 PM
Yepp, the middle ground here is sending them out for a rebuild.
Title: Re: OM617 Injectors Should I test them or just replace them
Post by: Diesel 617 on 03 March 2019, 04:33 PM
Quote from: Alec300SD on 03 March 2019, 02:54 PM
Send your new nozzles amd used injectors to Mark (forum member Greazzer) at https://dieselfuelinjector.guru/

He has rebuilt mutiple unjector sets for me and  many others.
He does top notch work at a reasonable fee

This route 100%
Title: Re: OM617 Injectors Should I test them or just replace them
Post by: Mergyver on 05 March 2019, 04:23 PM
Thanks for the tip guys. I reached out to Mark and got the details. I will have him rebuild a set for me. Trying to decide if I should go with stock injectors or something like the Monarks. Does anyone have any recommendations?
Title: Re: OM617 Injectors Should I test them or just replace them
Post by: Diesel 617 on 05 March 2019, 10:56 PM
Get these
https://www.ebay.com/itm/5-X-MONARK-NOZZLE-F-MERCEDES-OM617-TURBO-NATURAL-DIESEL-MADE-IN-GERMANY/323358559478?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

Unless you find them for a better price, this is the best price  I have found
Title: Re: OM617 Injectors Should I test them or just replace them
Post by: OLDGOLD on 06 March 2019, 08:18 AM
Monarks all the way! The engine sounds much smoother and there is no more "nailing" at low speeds. Just have your existing injectors rebuilt with Monark's, no need to replace the entire injector.
Title: Re: OM617 Injectors Should I test them or just replace them
Post by: Mergyver on 13 March 2019, 12:21 AM
Looks like Monarchs are the way to go. Thanks for the input.
Title: Re: OM617 Injectors Should I test them or just replace them
Post by: Mergyver on 04 April 2019, 10:16 PM
Hey guys, I just wanted to follow up with a final report on where I ended up with this.

I took your advice and contacted Mark Blevins at dieselfuelinjector.guru . He set me up with a set of rebuilt injectors using NOS #1930 nozzles, new washers return hose, plug, and over flow valve spring. He turned them around very quickly, did a nice job at a good price.

They have made a huge improvement in the way the engine starts and accelerates. I am very happy so far with his work.

I have put about 150 miles on them so far. I am really looking forward to seeing if they make any difference in the MPG. I will report back after a couple of fuel tank fill ups.

Regards