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.

Hard to start when warm is not specific enough. Do you mean its spins over slowly when warm or it spins and spins but doesn't fire? If its not a starter issue with slow turning of the motor, then it may be a fuel supply issue? Might also be losing fuel at highway speeds resulting in the lower mileage?

__________________
You can't always get what you want, but if you try sometime you just might find you get what you need.

Clarification: When hot, the engine cranks over just as good as when cold but when coolant temp is 80C or warmer it is as if the glow plugs are not working as well. Sometimes it will start but many times it will not. The engine cranks but does not fire well enough to start. It is as if the valves are way out of adjustment. But I have adjusted them to the specs in the FSM. I have a another 300sd that I've adjusted the valves on. It runs great!

this makes me think the car was run on WVO... low compression coupled with difficulty hot starting... ya see, the poorly dewatered WVO tends to eat up the injection pump, keeping it from adequately building spray pressure with warm thin fuel...

try dumping cold water on the IP and see if it starts better...

if so, you may want to find a better condition IP, (I've got a few) and soak the cylinders in MMO for a week...

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Hmm that's a possibility. I didn't think about the IP because it runs just fine as long as I don't kill it. I have experience with the slow failing of the IP on my 93' all mechanical 6.5 Chevy turbo diesel. This pump could definitely be showing its age in a different way being an inline Bosch vs. My Chevy's rotary stanadyne db2 IP. I'll have to give that a try when I get a chance!

Have you done a compression test? What are the numbers?

__________________
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