Diesel equivalent of “vapor lock” ?
 

Excuse my ignorance here, I’m still learning about the idiosyncrasies of diesels.

What would cause a diesel engine (1984 300D, ~200,000 miles) to be significantly harder to start when warm than when it is cool? It takes a good 5-8 seconds of cranking to get it fired up well enough to keep running when it is hot. (It takes only about 2-3 seconds of cranking in the morning.)

Compression is good, injectors are *new*, IP timing is O.K. I have seen some mention of ‘delivery valve’ seals, and this seems like it may be applicable to this situation – however, I can’t find anything on the service CD about the replacement of those seals. Could someone please point me in the right direction? Or am I even barking up the right tree?

Much Appreciated

RTH

A stab in the dark, but I had a similar problem on a Ford 6.9 diesel. It turned out to be a weak starter, not turning the engine over fast enough when it was hot.

I would suspect the glow plugs first. Check to see if they are turned on when before the starter is energized when the engine id hot. You can do this by connecting a voltmeter (or a light if no voltmeter) to one of the glow plugs. They should be energized as soon as the key is turned on and stay on about 30 seconds.
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