My '04 PSD w/ 150,000 miles developed a slight miss while towing a fifth wheel. I noticed the miss at idle speed and shut the truck down. When I tried to restart, it would spin over but no start. I let it sit overnight and fired up the next morning. The miss was still there, but not quite as noticeable. Since then, I've noticed that the truck will crank if the engine is cold, but won't if it's hot. I chalk this up to an oil pressure problem... thinner oil, no start, thicker oil starts? I've replaced the IPR twice over the years. Could this be yet another IPR failure? Waiting to hear if anyone has heard of this before I pay the $$$ to have the truck taken 50 miles to the nearest dealer/service tech to pull codes.