im working on a friends ranger he had me put in new plugs and wires but the truck still drives the same come to find out the exhaust coil wont fire replaced the coil still wont work and theres power going to the pigtail for that coil so im stumped


thank you for the help
BasicConcepts

 

I would start by checking the other wires in the circuit, they both come from the pcm. inspect the connectors for corrosion and check for continuity, and be sure they arent grounding out on the engine or chassis someplace.

 

Just a SWAG here but maybe there is a sensor on the timing wheel that needs to be replaced? I dont know but some vehicles that have had ignition problems that was the problem. Maybe someone with more knowledge can illuminate the rest of us?

 

Delete because of double post.

 

The coil packs have B+ to them at KOEO, BUT need the computer to provide the ground switching to cause spark. If one coilpack isn't functional, you should have a CEL lit & a trouble code for it stored in the computer, so scan the computer for codes & post ALL the code Numbers.

This system can use either the cam or crank sensor to operate the coilpacks & injectors if one of those sensors fails. If one is bad, there will be a trouble code set for it.

So seeing as how you have spark on one coilpack & you've replaced the troubled coilpack with no joy, that would seem to suggest a wiring, connector, or computer ground switiching driver problem as Phinxter has suggested, so check/flex the wiring & inspect the electrical connections back to the computers firewall connector on the troubled coilpacks circuit. If all that checks out, seeing as how Murphys Law is still alive & well, if you haven't already done it, do a resistance check on the new coilpacks primary & secondary windings, to make sure the new coilpack is ok & Murphy isn't messing with you!!!! lol
Ford doesn't specify a primary resistance value, but it should be about 1 ohm or less, the secondary should measure 13-15K ohms.

If you don't have a multimeter for the resistance check, if the wiring connector to the coilpacks is long enough, try switching the electrical connectors to see if the troubled coilpack wakes up. If it does, the coilpack is good. If the harness isn't long enough, you could swap the coilpack positions to see if the new one will make spark. If it does you'll know it's good & there is a ground switching problem for that coilpack position.

If the wiring & electrical connections check out, suspect a computer ground switching driver problem. A good electronic Tech should be able to replace the driver for a lot less than a replacement computer.

More thoughts for consideration, let us know how it goes.