Hope someone can help,,, my wife's pride and joy ,'90 conversion van , has developed a problem I cannot figure out . If driven long enough to get it warmed up , it will not restart unless allowed to set for at least 30 min. When attempting to restart in any less time , the engine will barely turn over . Jump starting with another vehicle will start it immediately . I've changed starters hopeing that was the problem but it wasn't , still acts the same . Thanks for any ideas !! Ted

 

Usually when you need to apply extra power to get a regular system to operate its because of high resistance at the battery terminals or in the battery cables. The first thing to do is make sure the cable terminals at the battery are clean and making good contact. If OK (you can't tell by just looking at them they have to be removed and cleaned) then the cables are corroded internally.
The best way to confirm this is to cut open the cable insulation at the battery terminal end and if you see the "Green or White Stuff" the cable is in need of replacement.

 

Any idea of why there is no problem with "cold" engine ??? Ted

 

Am having the same problem with my 95 E350 diesel van. Starts like a charm first time then after shutting down won't restart again unless I put a small spray of starter fluid in air filter. If I let it sit for a long time or overnight it starts up fine. Just had a lot of work done on it (new glow plugs, tranny work, new F & N filter, etc.) and it ran great until I made a trip with a flatbed trailer, started up fine after being loaded, got home to unload and it wouldn't start. Waited for a bit then it started fine and has done this ever since. I hate using starter whenever I go somewhere as I know it screws up the glow plugs but it's my work van and I need it to run. Have checked the terminals but not inside the cables (will go check it out now). Hope it works!

 

Just went out and cleaned all terminals and checked the cables which were clean inside. It still won't start tho-. Any more possibilities?

 

First , I think we're talking two different problems with two different engines.
From what I gather from your post, the starter cranks just fine, but the engine won't fire up. One thing to check would be the fuel solenoid to make sure it is opening enough for fuel to go where it must. There could be an electrical or mechanical problem there that would require further checking. There is also an oil press sensor that may not be functioning properly when hot due to lower oil pressure when hot. It's located right in front of the engine just behind the fan on top.