bucking bronco

[bdunegan]

i have a 1988 bronco 2 with the 2.9 v-6. starts and runs fine, except for speeding up and slowing down at idle, and everyonce in a while, a cutout while driving. speeds up from 800 rpm to 13 or 1400 rpm then idles back down immediately just while idling. just replaced both fuel pumps and filters, and fuel pressure regulator. i know it needs plugs and wires, but could this be the cause or something else.

[Truck]

Is this carbed, or FI? A carbed engine uses a "check valve" between the carb and the vacuum advance on the distributor. If you don't see one, or it's in bad shape, you should try replacing it. (A check valve keeps the timing correct when the throttle moves...advancing for load, then keeping advanced while re-starting.) A friend of mine just (yesterday) got a check valve for his Chevy (forgive me) and it runs a ton better now.

[bdunegan]

mine is fuel injected. like i said it surges like this in the morning when i let it warm up, and then an ocasional cutout while driving. i just knicknamed it bucky. could my plugs and wires be doing this. i know it needs them.

[Truck]

It's probably not the pugs or wires, if it ever runs smoothly. What it could be is the ignition module. Those are most prone to act up once it gets hot. (that's the 7th lead off your distributor...a haynes manual tells you how to check them.)

[bdunegan]

i may have been misunderstood, so i will try again. my bronco runs fine when warmed up except for a cutout once in a while.(i am getting gas out of a small company tank, so it may be a water problem there). the surging comes when it is first started in the morning until it warms up, then it does fine.