I know this topic comes up every once in a while. Now that I have at a few thousand miles behind the wheel, I thought that I'd relate an entirely unemperical observation.

The PO bought Bosch reman injectors (India) and installed them 2-3 years ago. He didn't buy just the nozzles, but the entire injector for about $40 each. So these would have supposedly ready to go out of the box.

He probably put about 1,500 miles on them and I drove another 2,500 miles or so.

Before I rebuilt the IP this January, I was getting about 25 mpg highway. After the injection pump rebuild, that number climbed to 27 mpg over the same roads. I should also add that I had them out last fall and they were sent off to be checked with no anomolies noted.

A few months ago, one started to nail. Shortly thereafter, I noticed some wetness on injector #2. So, I bought a set of used 135 bar injectors from a gentleman on this board and had them cleaned up by a professional Bosch shop. They were adjusted to pop at 140 bar. If you're keeping track at home, that's a full 25 bar over spec for a W115. Also, the shop said that although the nozzles weren't "leakers" they were noticeably worn. The shop also checked that leaky #2 and felt that it wasn't lapped properly.

Anyway, I installed these injectors a few weeks ago in preperation for a major road trip (~1,100 miles). I also adjusted the valves.

I kept careful track of my fuel economy on the trip. Since I was travelling through different parts of the country with varying terrain (steep hills in WV and southern PA and rolling hills and flat terrain on into central NY), I topped off the tank several times to get a feel for how she does in each section.

The result? I averaged 27.6 mpg for the trip. I even got 30.0 mpg on one 200 mile stretch of interstate and back roads from MD back into WV. This is after correcting for 2% inaccuracy in the odometer and topping the tank off by hand once I returned home and was parked in the garage.

The moral? I don't entirely know.

At a guess, though, it seems to me that old, worn original Bosch nozzles set 25 bar over spec perform *at least as well* as new Indian remans...at least in my engine.

If I were to take it a step further, I'd submit that they perform slightly better. But since I didn't have as much "testing" with the remans, I'd be afraid to dismiss them outright in terms of fuel economy. Build quality is another matter, however...

I realize that this is nothing more than antecdotal, as best. But given the time and expense involved in doing these sorts of tests I thought that I'd pass on my experience.

I have a set of Bosio nozzles coming. In a few weeks I hope to have the same shop rebuild another set, this time set to perhaps 125-130 bar. I'm curious to see how these stack up to the old Bosch.

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1974 240D "Boldie" 170K.- New timing chain/freshly rebuilt IP/replaced valve seals/injectors/upgraded stereo/new Bilsteins with Yokohamas/fresh paint and rocker panels plus lots of welds.

All I can say is that there's recently been a similar discussion over on BW

Monark injectors--the whole injector - Benzworld.org - Mercedes-Benz Discussion Forum

It is good to hear from your experience that the old is better than the new (even when they are a bit worn).

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

The moral for me is that I wouldn't install $40 injectors.

This car is ready to be sold at Ebay.

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[/SIGPIC]~cirrusman

1983 Mercedes Benz 300SD - Wife calls him "Chitty Chitty Bang Bang"
[SIGPIC]




1983 Toyota Tercel (Tommy, The little Toyota that could)
1965 Ford F100 (Grandma Ford)
2005 Toyota Sienna (Elsa, Wife's ride)


Gone:
1988 Toyota Pickup
2004 Subaru Outback

1987 Cadillac Fleetwood Brougham
1986 Volvo 740 GL Station Wagon - Piece of junk.
1981 Volvo 242 DL 2 Door - Hated to see it go. R.I.P.
1987 Pontiac Fiero GT

See Post #3. A Guy that works in a Fuel Injection Shop has that the Rebuilts from Mercedes are better than the Bosch Rebuilts you get from other sources.

best injectors for a 617.952 engine | Mercedes-Benz Club of America

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84 300D, 82 Volvo 244Gl Diesel

He claims the following: "Bosch OEM... I'll put it this way... this week I had a client without funds to purchase genuine MB injectors, so they opted for Bosch OEMs at lesser cost to them."

MB doesn't make injectors. If somebody orders injectors from MB, MB sends an order to Bosch, Bosch sends an injector to MB, MB sends the injector to the client.

But why do you want to buy an entirely new injector? Why not rebuild them with new nozzles. Have it done by a reputable diesel workshop if you cannot do it yourself.

What I got from His post is that the Injectors that are rebuilt and Boxed for Mercedes have an opening pressure that is such that all the Injectors you get from Mercedes will be within what Mercedes considers a Balanced range.

If you rebuild a lot of Injectors this is easy to do. As, an example when you test the Injectors you put all of the Injectors that fall within the Range that Mercedes wants into one Bin and see to it that they get into Mercedes Boxes.
(Where I used to work we did the same things with Detroit Diesel and Cummins Injectors but with the Flow. The ones that Flowed the same were put in a seperated Bin till there was a set that flowed the same and then we would box a matched set.)

The rest that fall into an acceptable but wider range of opening pressures you slide the Rubber/Plastic Band with the NA Xsomething over the Injector and put them in the Bosch Boxes.

Remember that Guy who at the time of the Post was working in a Fuel Injecton Shop is giving is observations on what he sees in the Real World.

What I recall Him recommending is that if you buy a set of OEM Bosch rebuilt Injectors that you should have them Pop Tested so as to turn them into a balanced set.

Also in his post He does not seem to have a specific opinion that He is pushing.

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84 300D, 82 Volvo 244Gl Diesel

I know...30mpg is pushing it on these cars, but it is what it is.

That being said, I limit the speed to 55-60 mph on the interstate (limit is 70 here in WV) and avoid using the passing gear on inclines. I let the car slow to whatever speed it wants to pull and get into the truck lane. The particular stretch that I got 30 mpg involved a lot of back roads where I slowed down even more. So, I'm sure that being easy on the throttle had no small part in the final results.

I also just did a fresh oil change, adjusted the valves, rebuilt the IP, and have my new tires inflated to 34 psi among other things.

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1974 240D "Boldie" 170K.- New timing chain/freshly rebuilt IP/replaced valve seals/injectors/upgraded stereo/new Bilsteins with Yokohamas/fresh paint and rocker panels plus lots of welds.

This is probably the most accurate take away.

It stands to reason that mass assembled fuel injectors with questionable quality control can't compete with experienced and reputable injection shops.

If there's any interest I'll try to do the same sort of test with the new Bosios. I'd also like to compare Monarks at some point. However, the time and expense might not justify what will probably be only a modest, if any improvement. Provided that your engine and the rest of the fuel delivery system are great shape then, lifespan aside, arguing one new injector nozzle over another boils down to splitting hairs.

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1974 240D "Boldie" 170K.- New timing chain/freshly rebuilt IP/replaced valve seals/injectors/upgraded stereo/new Bilsteins with Yokohamas/fresh paint and rocker panels plus lots of welds.

I'm interested to hear how that goes.

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

So the only difference between Bosch injectors bought from MB and Bosch injectors bought from Bosch is that Bosch sets the opening pressure too far from the supposed opening pressure?

In the real world workshops send injectors to diesel workshops to have them rebuild and set at the correct pressure. And you don't just rebuild one injector, but all of them, so that they all have exactly the same opening pressure. If he want to sell "genuine" MB injectors to a client, that is his choice, but that is the most expensive option.