1986 Ford Bronco runs rough

My 86 Bronco runs rough, misses when I accelerate.Changed fuel pump and filter. No change. What other possibilities for this condition? Any assistance would be greatly appreciated.

86 Bronco?

Are you using gasoline that contains ethanol?


Worn out Spark plugs
Arcing Spark plug wires
Cracked Distributor cap
Worn Distributor Rotor
Dirty Air filter


My opinion as always is to run a compression test and find out whether or not the engine is dying because of a cylinder(s) dropping.

If compression is down then you can throw parts at it untll Kingdom Come without curing anything.

Another possibility since this is a TFI model is that the ignition timing could be off if anyone has dinked around with the distributor and not disconnected the SPOUT connector while doing so.

Good ideas above. That’s where to start. Next, bring all the routine engine maintenance Ford suggests up to date. Next do a thorough test of the vacuum system. If you still got the problem , replace the pcv valve. Next replace the spark plug wires, the distributor cap, and the ignition rotor. Still a no go? There’s a gadget called an “octane rod” for the V6 177 in the distributor than can wear out and cause engine performance problems. Cleaning or replacing the injectors might be necessary too. It might pay to have this problem diagnosed by a Ford pro, they’ll tell you what the problem is, then you can fix it yourself if you like.