Went to crank up the 84 300TD today and it wouldn't turn over. It was parked on a hill nose up so I'm thinking it may have gotten some air in the lines. How can I tell if it's that or glow plugs acting up? I don't have a lot of time to diagnose since I need to drive it tomorrow morning. The last time I had some cranking issues it was heat related and would end up turning over after a while. This time I can't get it to go and there does not seem to be smoke.

Am I right to try the lines first?

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"Gerwalt" 1984 - 300TD

If the engine is not turning over, the problem is electrical. If it's turning over but not firing, almost always the first suspect should be glow plugs. Check for voltage at the plugs with the key in the glow position. After that, check each plug thru the harness unplugged from the relay for the correct resistance. After that, pump the primer pump.

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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

Sorry, yes the starter is working but the engine just isn't firing up.

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"Gerwalt" 1984 - 300TD

The simple answer is

Lack of smoke =
* Glow plugs not working.
* No fuel.

#1. Electrical issue.
#2. Air entering the fuel system.

.

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probably air in the lines. if the return line is cracked or has a loose connection air will come in and drain fuel from the pump.It siphons back into the tank so you never see any fuel leak. put new lines on mine. Also went to the auto parts store and got an electric fuel pump to put in the line from the tank and run it off a separate switch to prime the pump for this and if I run out of fuel.

I think your 84 has a hand primer on the side of the pump which will prime it. my 90 350 pump is supposed to be self priming but that is a joke.

Got it running. I backed it down the hill to a slightly lower grade and hooked up a battery jump charger to aid in the juice. Also tried pumping the primer a little but that thing leaks a lot so I don't know what good I did there. (Might be time for a Diesel Giant bulb pump?). Anyway, she fired up after a bit of cranking and sputtered some but eventually evened out.

Thanks all.

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"Gerwalt" 1984 - 300TD

If the prime pump is leaking, personally, I would replace it. I don't know if that will cause air in your fuel system (I suspect it would), but if you're having fuel issues, fix all the leaks.

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