86 f150 5.0 my truck has been running rich and rough and I can't figure it out. Looking over everything I seen a loose unconnected wire from the main harness where it plugs into the injector harness. The same amount of wires in the main clip as in the injector clip but the other wire is about the same length but I see no where for it to go. I'm not sure if it's supposed to or not. ???? The code I had was lack of tach to eca. Thanks for any info

 

what color is the wire? Maybe I can find it in my diagrams

 

I'll have to look tomorrow. It's at my dad's in his garage. I wrote it down but can't find it

 

Just a shot in the dark though considering your problem. Make sure the SPOUT connector is hooked up comming of your distributor. I have never been able to look closely at one of these engines so I dont know exactly what your talking about but maybe that wire is that connector

 

Just got around to looking at it. The wire is orange. Where the injector harness snaps into the main harness. This wire is coming from the main harness. It's not the spout it's up by the distributor

 

Look at it carefully. Does it have a faint white stripe? If so, it feeds power to the map, the tps, and the egr position sensor. On terminal #26. There is also a orange wire coming off the TFI module. My diagram says it's orange, the diagram below says it's black/orange.

 

This sounds strangely familiar. Had a fuel pump relay issue with my son's 86 F150 and found an orange wire disconnected by the left rear corner of the engine off the main ECU harness. Turned out to be the ground for pin 49 of the ECU. Grounds to the left rear corner of the intake manifold.