1969-350B won't start

[Mgoldsmith]

I purchased a well kept 350B with backhoe in May. It ran strong with no smoke. From May through June I started it once a week and it ran great.
The crawler sat for a few weeks and I tried to start it and it was hard to crank. I replaced the batteries and now it cranks great but can not get it to start even with a little help with some starter fluid while cranking.
It emits black warm smoke like it is ready to fire but wont.

I replaced the rubber fuel lines from the tank to the electric fuel pump and bleed the system to the injector pump. Cracked front injector line and get fuel but did not check the other two

Replaced electrical lines from the switch to the injector pump and fuel pump. There were many splices.
Removed all electrical connections cleaned and reinstalled
Re attached neutral safety switch wiring.
Cleaned air filter
Have not replaced fuel filter yet.

Could it be clogged injectors?
Bad compression does not make sense to just stop running when it was OK a few weeks before
Stuck lifter?

Suggestions please.

[original possum]

Only three things are required for a diesel - fuel, compression, and timing. Timing is the least likely to fail. Do the basics.

[Tigerhaze]

Maybe after sitting you got some water condensed in the fuel tank?

[DukeofDeere]

How much either are you giving it?
Duke

[DukeofDeere]

Time for a filter change and bleed the system.

Duke

[Mgoldsmith]

Update on no start
The suggestions have been helpfully
Fuel tank was filled with off road diesel with stabilizer .no water in fuel or filter
Either shot was short vapor only while cranking. I used to work on marine Diesel engines so I known the pros and cons

A suggestion to check the tank filler cap to make sure the vent was clear lead to an interesting find. The cap has no vent and when unscrewing the cap it was like opening a jelly jar. With no way for the tank to vent it caused negative pressure causing the fuel not to be pumped and staved the engine.
There is a valve stem next to the filler cap. I have never seen this before. Is the tank to be pressurized with air?

So the engine started but only for a few seconds. At least it fired
Next step. Re bleed the fuel system and replace the filter

[Scottyb]

the vent is under the cap. It goes through your tank and out the bottom. push a welding rod or coat hanger through and open it up. Yours must be plugged

[rock digger]

That is there to aid in bleeding the fuel system, I had a 1948 D4 that an old guy put one on. If you run out of fuel you fill er up and pressure the tank and out the fuel comes from the bleeders b4 you know it. Try runing with the cap loose and you will find if the vent is plugged.

[Mgoldsmith]

Thanks for everones input
Finally got the baby running.
This was a comination of a clogged fuel tank vent, air in the line ann the biggest and sillest thing, Hydraulic back pressure. Yes I had not reconnected the main lines off the backhoe attachement when repairing some lines. The coupler was not fully connected causing the hydraulic pump to not flow through and created too much back pressue for the motor to run.

So now it's time to replace all the guages and get the lights to work.
I think the voltage regulator may be bad. Is there a cross reference or usabe automotive regulator that can be adapted?

[Lavoy]

Different than any automotive I believe, but not hard to get.
Lavoy

[NWJD fan]

It may be more economical to replace the Motorola alternator with a Delco 1 wire alternator with built in voltage regulator. You may have to machine out the bore of the drive pulley on from your Motorola alternator to fit the Delco but otherwise pretty much bolts on. Isn't it interesting how a series of small problems can accumulate into something that seems like it might be major?