664 clark engine

[rockwall]

A friend has a Clark 664B with 353 Detroit. In the winter he would plug it in for an hour or two and then hit the button and bam she would start right up. Lately, plugged in and hit the button and she turns over but won't start. If he hits it with a shot of starting fluid it fires up. What could explain this? Thanks

[rusticretreater]

Weakening glow plugs.

[rockwall]

no glow plugs, thanks

[barbender]

I'd say his block heater or the cord failed. Not unheard of.

[rockwall]

Thank you, I will tell him, that's a good place to start. Tom

[KWood255]

Could be a variety of potential issues. First, check the block heater. Secondly, I would ensure the air filter is clean, followed by fuel filters.

As with all naturally aspirated engines, these Jimmys need fuel, air, compression and exhaust to run. If it was running well earlier, go over the basic maintenance issues. Short of these, he could have an injector failure on one or more cylinder to make it lazy to start, or a lack of compression although somewhat unlikely unless the engine is worn or had a failure. 

When it does fire up, what colour is the exhaust (especially once the motor is warm?) As a rule of thumb:
-Black smoke....over fuelling and/or shortage of air intake
-Blue smoke...oil burning
-white smoke...could be an injector stuck open (flooding cylinder) or lack of compression causing unburnt diesel fuel
-clear exhaust = ideal operating engine

My 664D is lazy to start, but once it's running it's a gem. I think it just needs a tune up, and the governor set properly for a little higher idle. My 230D after the above mentioned tune up starts immediately and purrs all day like a Swiss watch. Luckily for me, my Dad was a Detroit diesel mechanic for many years. While he cannot remember my phone number, he will recite torque specs upon request for a jimmy lol. 

[62oliver]

I had this issue with my 453 awhile back.

There is a check valve in the fuel system, if I remember correctly, it is in the head of one of the fuel filter housings.

If it gets a bit of dirt in it the fuel will drain back making it difficult to start.

On mine it cleared itself up before I actually got to digging in and trying to fix it. That sort of confirmed to me that it was the problem. 
 
Also check for water, change fuel filters.