om617 Hard to start when warm

[mattchatman@gmail.com]

Ok all I've got a problem with an om617 out of a 1982 300sd. I swapped it into a 97' jeep wrangler. The engine has somewhere between 200-300k miles on it, the odometer didn't work when I bought it and I drove it around for a while before I bought a nicer 1983 300sd and pulled the engine out of the 82' for my jeep swap The engine has low compression but it starts just fine in temperatures above freezing. The hard starting arises after the engine is warm.

Things I've checked/done:

*Valves: adjusted
*Timing chain stretch: 2 degrees
*Compression: 5:250 4:225 3:200 2:180 1:170 (awful I know)
*Injector pump: Timed
*Vacuum kill switch on Injector pump: Functioning Properly (I've tried disconnecting it completely from vacuum)
*Glow plugs: working- although possibly not glowing as long when engine is warm?
*Replaced front crank seal


I know the compression is terrible but I have good oil pressure and it runs just fine as long as I don't kill it after it is warm. Again, after sitting for a while it will start down to around 32F. I just don't know what else it could be other than a blown head gasket or cracked head but it doesn't use much oil and doesn't use coolant. There is no water in the oil or oil in the water. It seems so much like valves but i've checked them several times. I'm going to bypass the glow relay just to make sure that isn't responsible somehow. Any other ideas I'm all ears!!! I'm fairly sure I've got a bad injector or five but I don't think that would cause hard starting when warm. I appreciate any input! Thanks guys!

List of symptoms:

*Hard to start when warm
*Poor highway fuel economy (it is a jeep wrangler with brick like aerodynamics) But It gets 24mpg around town and only 18mpg running 65 on the highway. I find that odd.