Hello, I have an 86 f150 XLT Lariat that has an engine swap from an explorer I believe. It is a little custom built but mostly 302. I was driving it and about to leave a lot when the truck started to die. It was very bouncy RPM and then quit. We towed it home and began to look. The distributor rotor turns, the battery is charged, and the fuel rail has pressure. The fuel pump comes on and will operate as normal. When we pulled off the first spark plug wire, it had a spark. The second didnt. So we used the first wire on the second prong and it till didn't spark. The ignition system is an aftermarket MSD distributor and ignition coil. The cap is clean and does not have any damage to it. The throttle body does have oil in it, but the air filter is a K&N cold air intake that requires to be oiled. When the truck sits for a while, it will start and run for about a minute and then die and not start again. I did get it started at one point by pumping the gas and getting it to rev high for a second. It sat there and then began to lower RPM again and then it died. I have no idea what would cause only one of the 8 prongs on the distributor to fire.

 

Welcome to FTE.
This MSD system is it a stand alone dist. or does it use the MSD box as they have 2 different setup?
If it uses a MSD box that uses a rev-limit chip pull the chip, think it will still run, and see if that does anything.
Is it just that #2 that has no spark or all the other no spark? Thinking all you get is that first spark then nothing else.
I think the MSD site has a section on how to check their systems but have not been over there in a bit.
BTW I have the whole MSD setup with 6AL box in my drag car and why I know a little about them.
Dave ----

 

He said "fuel rail". Is this engine carbed or fuel injected?