The van starts fine when at non operating temperature but after it runs and warms up and i turn it off THEN try to start it i have to wait for it to cool down to get it to start.(it's just warm not overheated ) what do you think wrong with it ? it's a 1995 351 5.8l e350

On engines with belt-driven cooling fans, a fan clutch is often used to save energy and reduce noise. The fan clutch disengages slows or disengages the engine's cooling fan when extra cooling isn't needed. The fan pulls air through the radiator and air conditioning condenser when the vehicle isn't moving fast enough to provide adequate airflow for cooling. A fan can eat up anywhere from a couple of horsepower up to 12 or 15 hp on a big V8, so by reducing the parasitic horsepower loss on the engine the fan clutch makes a noticeable difference in fuel economy.

A slipping fan clutch is often overlooked as the cause of an engine overheating problem.

As a fan clutch ages, fluid deterioration gradually causes an increase in slippage (about 200 rpm per year). After a number of years of service, the clutch may slip so badly that the fan can't keep up with the cooling needs of the engine and the engine overheats. At this point, replacement is often necessary.

Other signs of fan cluch failure would include any looseness in the clutch (check for fan wobble), or oil streaks radiating outward from the clutch hub.

If the clutch is binding, the fan may not release causing excessive cooling and noise, especially at highway speeds

CHECKING THE FAN CLUTCH

A good clutch should offer a certain amount of resistance when spun by hand (engine off, of course!). But if the fan spins with little resistance (more than 1 to 1-1/2 turns), the fan clutch is slipping too much and needs to be replaced.

If the fan binds, does not turn or offers a lot of resistance, it has seized and also needs to be replaced.

Fan speed can also be checked with an optical tachometer, by marking one of the fan blades with chalk and using a timing light to observe speed changes, and/or listening for changes in fan noise as engine speed changes.

You should also try to wiggle the fan blades by hand. If there is any wobble in the fan, there is a bad bearing in the fan clutch, or a worn bearing on the water pump shaft. A bad water pump bearing will usually cause the water pump to leak and/or make noise, but not always. Remove the fan clutch and see if the play is in the water pump shaft. If it feels tight (no play or wobble), replace the fan clutch.

I posted this to another Ford Problem and I believe it applies to you as well.

This is a shot in the dark with out running diagnostics myself but here it goes, I had a 1988 Cavalier that would just die while I was driving it. On short drives, in the morning, when the engine was cool... it would not die. It would only die after the engine heated up to a certain point.

I took it all over the place to see what the problem was and nobody could figure it out, until finally I took it to my local Firestone shop and they had a special diagnostic tool that checked all of the electrical connections and low and behold I had a misc. wire that crossed the back of my engine from one side of the engine bay to the other. This wire was melted to my engine block and when the engine heated up to a certain point the wire would short out.

After they pinpointed the wire they replaced it with an in-tact wire and it worked beautifully.

Again, I am not stating that this is for sure your problem, but take it from me that there are better diagnostics to run then your standard error code ODB II dump.

Hope that helps and let me know if there are any developments.

Brian