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1985 300D, 1978 300CD, 1985 300SD
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46 Posts
Discussion Starter · #1 ·
85 300dt doesn't want to start cold. It was 70 degrees here today. The only way it will start is with help of starting fluid.
To date I have:
New battery
valve adjustment
new fuel lines
used injection and alge cleaners in fuel
glow plugs getting power
installed new rubber and cooper o ring at fuel filter
replaced both fuel filters

when tying to start cold it acts like it is not "turning over' fast enough to get started.
 

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83 300 d t
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699 Posts
try new glow plugs dont use starting fluid very bad for engine . run compression test mabe low compression would cause your problem to .
 

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1983 240D auto..soon to run a generator in the country.1984 300D turbo 4 spd
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149 Posts
I've found low compression lets the starter turn quicker than usual. If you're sure your starter's in good condition I'd check power to the starter. I assume once the engine's started it runs at normal rpm thus nothing else slowing rpm. If you pull the glow plugs, should spin like a top. Compression test (already suggested) and confirm starter.
Luck
 

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1984 300D Turbo
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1,606 Posts
verify all glow plugs are good. starter must spin the engine at least 100rpms to start.
 

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1985 300D, 1978 300CD, 1985 300SD
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46 Posts
Discussion Starter · #5 ·
I stopped to see a old diesel dude this morning and he thought it might be a place in the fuel system that is allow air to get in. If so where are the first place to look to trouble shoot air in the system?
 

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1985 300TD Wagon
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408 Posts
Air in the fuel lines can cause problems in diesel engines, OM617 is not very sensitive for this. It's normal to have air in the small fuel filter. I've never seen air being sucked in with diesel like this. Only leakage of fuel occurs as far as I can tell. The 601/ series does have this problem now and then. That's why your diesel guy say so.
Because you say this is happening when the engine is cold my first thought is: what kind of oil (and in what shape & age) is in it?
Old oil will get thicker especialy when cold, causing the starter to slow down!!
 

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1984 300D Turbo
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1,606 Posts
hamsanwich81 said:
I stopped to see a old diesel dude this morning and he thought it might be a place in the fuel system that is allow air to get in. If so where are the first place to look to trouble shoot air in the system?

primer pump is a likely culprit.
 

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1985 300D, 1978 300CD, 1985 300SD
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46 Posts
Discussion Starter · #10 ·
thank you all for advice I just figured out the wrong spin on fuel filter was put on with out the two o rings ( copper and rubber). I'll have to wait till it is dead cold to see if that was it . I have feeling that sure did not help but i doubt it will fix the cold start problem. will respond once i test it thanks again
 

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Registered
1985 300D, 1978 300CD, 1985 300SD
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46 Posts
Discussion Starter · #11 ·
well that di dnot fix it but i thinkf it helped, seems more powerful. next i think I'll check fuel strainer and maybe order some new glow plugs. thanks again
 
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