I am having some injector trouble on my '81 300D(non-turbo) and I am trying to decide whether I should buy new injectors or used injectors that have been pop tested.

If an injector pop tests within the acceptable range, does this mean the nozzle is good?

Can an injector have a good pop test with a bad nozzle?

Will a good pop test ensure proper spray pattern?

If I buy the used injectors that have been pop tested I may replace the nozzles as well.

Anybody have any advice/ideas to offer?

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1993 W124 300D
-297K on the clock as I type this.

What is the price difference?

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01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

Bad nozzles can be in a otherwise good injector that pops at the correct pressure. If possible watch the injector in question and see that it does not "pee" but instead sprays. Nozzles are a wear item- at say 100-150K.

I just found some Monark rebuilt injectors for $295 for the set of five including heat shields. $35 core charge will be refunded.

I found a set of five injectors on Ebay and the guy agreed to sell them to me for $75. He pop tested them all and they are within range. I am waiting to hear back from him to find out how many miles are on them and what the spray pattern looks like.

I have found a set of Monark nozzles for about $120 shipping included. I don't have a tester though so I would be going blind if I were to just replace the nozzles without testing them.

I read DieselGiant's writeup on rebuilding them yourself and he never mentions pop testing them when he's through. Do you think this is an oversight or you don't need to test them?

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1993 W124 300D
-297K on the clock as I type this.

Pop testing tests the pressure with the nozzles that are installed. When you change nozzles the previous pop testing results no longer apply. If you are going to install new nozzles there is no reason to buy injectors that have been previously tested. If the injectors you are looking at have been pop tested and have a good spray pattern go ahead and run them without changing the nozzles.

Pm sent.

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1987 300D (230,000 mi on a #14 head-watching the temp gauge and keeping the ghost in the machine)
Raleigh NC - Home of deep fried sushi!

hey Sean, Im in the same boat, would you pm also...

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1983 W123 300D Turbo
2000 F250 7.3 Powerstroke

I'm dittoing what MTUpower is saying...Personal preference. Not always.Yes it can.

No, pop test refers to the minimum pressure the nozzle first opens.

If you decide to do it yourself, you MUST be absolutely as clean as possible -- along the lines of operating room or NASA clean room.

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1987 300D (230,000 mi on a #14 head-watching the temp gauge and keeping the ghost in the machine)
Raleigh NC - Home of deep fried sushi!

Perhaps one other way is to send your injectors to Sean if he will test them and rebuild hem if necessary. If you buy somebody's injectors, you are at their mercy as far as whether it pops and sprays well.

__________________
01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

If you get used injectors be sure they have been checked for proper pop pressure AND spray pattern. If you opt for rebuilt injectors I rebuild injectors for members here for much less than the $295 you were quoted.

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

I bought some used injectors with only 70,000 miles for a $100.last Year.I can't wait to buy rebuilts with Monark nozzles.Don't buy used injectors.People lie like Dogs.

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1999 w140, quit voting to old, and to old to fight, a god damned veteran

I purchased new nozzles (bosio). Is there any need to pop test these before install, or can I just put them in?

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Thanks!
Joe.
82 300D turbo
169K mi.

Yes. Otherwise how will you know hat shims to put in to set the pressure?

__________________
01 Ford Excursion Powerstroke
99 E300 Turbodiesel
91 Vette with 383 motor
05 Polaris Sportsman 800 EFI
06 Polaris Sportsman 500 EFI
03 SeaDoo GTX SC Red
03 SeaDoo GTX SC Yellow
04 Tailgator 21 ft Toy Hauler
11 Harley Davidson 883 SuperLow

He failed to do the job properly. I replaced my nozzles and one of my injector's pop pressure was way off. You'll never know unless you pop test them. Yeah, it might be close enough and get you by; but if you want it done right, you need to pop test them.

Scott

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Scott
1982 Mercedes 240D, 4 speed, 275,000
1988 Porsche 944 Turbo S (70,000)
1987 Porsche 911 Coupe 109,000 (sold)
1998 Mercedes E300 TurboDiesel 147,000 (sold)
1985 Mercedes 300D 227,000 (totaled by inattentive driver with no insurance!)
1997 Mercedes E300 Diesel 236,000 (sold)
1995 Ducati 900SS (sold)
1987 VW Jetta GLI 157,000 (sold)
1986 Camaro 125,000 (sold - P.O.S.)
1977 Corvette L82 125,000 (sold)
1965 Pontiac GTO 15,000 restored (sold)

While you are making sure the injectors are set to right pressure and have good spray pattern... is a good time to make sure the precombustion chamber pintle and holes are in good shape... otherwise that careful work will be wasted.