When cold, my 84 300D requires 6 to 7 starting cycles to turn over. I've replaced the fuels filters and run a couple of cans of Diesel Purge through it.

Any suggestions as to what I should go to next?

Sounds like you have glow plug issues.

Try "ohm"ing out the glow plugs to see how many are bad,
we can go from there.

__________________
81 Mercedes 300SD 289k.......SOLD
82 Mercedes 300CD 252k......slow ride

82 mercedes 300 SD...mi Unknown
83 Mercedes 300D ????ksniff..gone too
84 Mercedes 300D 148k........SOLD
85 Mercedes 300TD 386k and holding some one elses project

You probably mean 6 or 7 cycles to start. You "turn over" the engine with the starter. It doesn't require glow plugs to turn over, but it does require glow plugs to start. Lets ask two basic questions. First are the valves properly adjusted? Next, do you have any idea of how much compression the engine has?

__________________
Junqueyardjim
Christianity, if false, is of no importance, and if true, of infinite importance. The only thing it cannot be is moderately important. C.S. Lewis



1983 Mercedes W123 240D 4 Speed 285,000 on the road with a 617 turbo, beautiful butter yellow, license plate # 83 240D INDIANA

2003 Jaguar Type X, AWD. beautiful, good mileage,
Mom's car, but I won't let her drive it!

That's what I figured... Thanks JackG

Great, and I was hoping it would be easy...

Valves and compression check! At least I'll have something to do on weekends...

Thanks JYJ

The number one cause of difficult starts on 617 diesels is bad glow plugs. Is your glow plug light coming on? Have you checked for voltage at the glow plugs? Dieselgiant.com has a tutorial on how to check the glowplugs. It would be a good place to start.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

I checked the glow plugs and leads and all items registered resistance of 0.4 to 0.7 ohms. I did not however perform a real power test on individual glow plugs.

I also installed 5 Bosio Nozzles...

Now it doesn't start at all!

I still think its the fuel system...

Any suggestions?

Have you checked for 12 volts at the plugs in the glow position?

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

I'll do that next!

If, while you were replacing nozzles, you got air in the fuel lines, the engine could be hard to start.

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

Checked the voltage at each glow plug. 11+ volts DC at each...

I still can't start my 300D.
-I've checked the Glow Plugs 3 times
-Replaced the Injector Nozzles (Bosio)
-Replaced the Hand Priming Pump
-Replaced a couple of fuel hoses
-I've primed the fuel system a couple dozen times
-I loosened the flare nuts to the fuel injectors and turned it over to purge the air from the system

After applying this method, it sounds and feels like the engine wants to run but doesn't catch.

Does anyone know a foolproof priming method?

I believe that its a fuel issue but I'm at a loss....

Just to make sure. You have checked the resistance of the glow plugs I see. Have you also verified they are getting twelve volts when they should?

Not quite 12v . . . I'd put a jumper caple on, or a charger . . . if the battery is low it won't turn over fast enough either . . .

True. Also, when you loosened the nuts at the injectors, did you keep cranking until you got fuel out of all five injectors?

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Whoever said there's nothing more expensive than a cheap Mercedes never had a cheap Jaguar.

83 300D Turbo with manual conversion, early W126 vented front rotors and H4 headlights 400,xxx miles
08 Suzuki GSX-R600 M4 Slip-on 22,xxx miles
88 Jaguar XJS V12 94,xxx miles. Work in progress.