Here is what has been happening on my 1986 F250 consistently for the past two months.

Cold start is always fine. If you shut down and then immediatly start back up it starts great then also.

BUT, if you drive to somewhere, shut down and let the truck sit for about 30 minutes it will crank but will NOT start.

After the truck sits for about 2+ hours it ALWAYS starts.

Any suggestions? I have scanned this forum and learned a great deal about the FSS, but if that had failed I think the engine would fail to start at all times.

This past winter something else happened with the truck that may be related and/or may help someone else on the forum so I will describe:

at the bottom of the aft tank filler neck there is a coarse plastic screen, evidently due to age this thing had crumbled and fallen apart. Then it goes to the bottom of the tank and clogs the outlet. Once cleaned out all was well for a couple months then the new problem.

The new problem has occured while operating out of the front tank so I am not sure it could be related. I am thinking possibly other parts of the fuel system have been contaminated by these plastic pieces. I have replaced the filter and the truck has failed to start since then. I have kept the old filter and am going to open it and inspect...

thanks in advance for any comments, suggestions or just wild ideas...

 

Seems to me that in most cases if they wont start when warm its a worn out IP. Does it try to start or smoke any?

 

In "failure mode" it does not fire at all when being cranked. I have yet to have this happen when there was someone to help so I have not been able to get a good look at the tailpipe while being cranked. If there is any smoke it cannot be a great deal because I can't see it from the cab, but this is something I will take a look at.

Thanks for the suggestion!

 

The same problem happened with my truck earlier this year. I took it into get repaired and the problem was the injection pump.

 

the ip is dying

 

Guys, many thanks. I will get with my local diesel shop, I know they overhaul IPs but I have not called them yet for a WAG on the cost.

BTW, I was mistaken earlier when I said the truck had 270k miles...it actually just turned 300k this past weekend and the IP has never been touched so I have certainly got my money out of it!!

 

Thats impressive. Generally they are only good for about 100k miles, although there are always exceptions to the rule.

 

I have seen several get real close to 300K before they were replaced, but most of them were hard to start exactly like you describe.