I have an 89 F150 6 cyl. It had dual tanks, but I removed the front tank, and put in a new rear tank and rear fuel pump. I have broken down several times now. The engine just shuts off, and wont start. If I let it sit for a while, it starts right up. Does anyone have any idea what could cause this? It sounds electronic to me, but I have no way of checking it. When I had it towed, by the time it got to the garage, it started right away. It is an intermitent problem. Any help would be greatly appreciated.

 

If you can get some carburetor and choke cleaner and spray it into the air intake then see if it will at least run momentarily. If it does that would direct you to check out the fuel system. And that could also involve an electrical problem with the electric fuel pump providing the engine is fuel injected, is it or does it have a carburetor?

 

It is fuel injected.

 

The above check is still a good one to do. If you can , check if you have spark coming out of the coil to dist wire. Coils can open when they get hot and cause a loss of spark.

 

I had a similar problem. It was the ICM. It's mounted to the distributor and I guess it's really sensitive to heat. I replaced mine and it started right up and fixed that issue.

 

This could be a similar situation. The ICM is very sensitive to heat and that is why a replacement should come with a tube of heat sink compound that MUST be generously applied to the back of the ICM before mounting ,to transfer the heat away from the ICM.
Usually fixes the problem.