Ronny-
Your truck just needs a good shot of Aqvavit or two and it will be fine, or is that me. These are some excerpts from another diesel specific online reference area, hope it helps. I know a guy here that is having the same problem hes going to try the "oil in fuel" trick to see if that will work. I would use less than more if doing it.
No Start Hot
High mileage or otherwise worn injection pumps can produce a "no start" or a "hard to start" condition with an engine at operating temperature. Hot summer temperatures usually make this condition worse.
Elevated temperatures can affect the injection pump's ability to produce the necessary fuel pressure during a hot re-start. Usually, once the engine is started, it will run more or less normally, but will again be difficult to start once the specific conditions are duplicated.
The usual test for this condition is to mix clean new motor oil in with the diesel fuel at a concentration of between 5-10% oil. The introduction of oil will raise the fuel viscosity and usually allows a worn injection pump to produce fuel pressure levels high enough for normal hot starting. If your diesel engine starts easier with the treated fuel, your injection pump will need to be replaced. However, all other possible contributors to this problem need to be ruled out before replacing the injection pump.
Low cranking speed and/or low compression
A diesel is a compression ignition engine. Combustion occurs when the heat generated by the high compression reaches the flash point of diesel fuel.
A higher cranking speed doesn't allow as much time for the compression pressure to leak down during the compression cycle. If your engine cranking RPM is lower than you remember, you need to determine if the problem is caused by weak batteries, battery cables, or a bad starter. If your batteries and cables are good, and a jump from another good battery doesn't significantly increase the starting RPM, then the starter is probably close to failure and will require replacement. You should have seen a starting RPM drop at some point during the last month or so if the starter is going bad. Before buying any new parts, you should go over all of the battery terminals and cables to ensure solid connections. A corroded terminal can cause one battery to drop out of the circuit and put the full starting load on the one remaining battery.
The Stanadyne Injection pump requires a minimum cranking speed to generate sufficient fuel pressure. A higher cranking speed makes it easier for the pump to develop the necessary fuel injection pressures. Minimum cranking speed is 100 rpm cold, and 180 rpm at operating temperature.
Poor compression pressure rarely happens overnight. Generally, a diesel will get progressively harder to start over a fairly long period of time. Cold weather aggravates this situation and you should take ambient temperature into account when diagnosing a compression related "no-start" problem. New engines will have close to 400 psi of compression pressure at cranking speed and a high-time engine could be as low as 275 psi. If your compression pressure is close to 275, then it's probably time to think about rebuilding the engine. A high mileage engine can be helped with fuel conditioner, but if the situation persists and none of the above helps, you'll be faced with the expense of a complete or partial engine rebuild.
Cheers, rugger
