missing and its getting worse

[black beauty]

ok my bronco has had a little bit of a miss in it for awhile but now its kicked into high hear and gotten worse. so im wondering if the distributor and the 302 might be going out or if ive got a burnt valve or just a valve going bad. but anyway before it would miss at low rpms below around 1500-1800 now its missing at highway cruising speeds around 2100+ rpms. tell me what yall think before i tear into it.

1989 bronco 302 ci

4'' rough country suspension lift

35x12.50 maxxis bighorns

15x10 eagle aloys

headers and flowmasters with turndowns

3, 10'' mtx audio subwoofers

pretty smooth ride for what i do

 

[muddinlate86]

deff sounds like the dist.just had that happen to me and for some reason once it warmed up it would miss like crazy,chenged the dist.cap roter butt.and ign.mod. runs like a champ!

good luck

 

[Seabronc]

Could be distributor or plug wires. When was it tuned up last and when did you last change wires, rotor, cap and plugs? You could check for wires arching by using a spray bottle of water. After dark, open the hood, run the engine while misting around the wires. If they are breaking down, you will get a light show /emoticons/[email protected] 2x" width="20" height="20" /> .

Good luck,

>-

 

[BroncoJoe19]

Could be distributor or plug wires. When was it tuned up last and when did you last change wires, rotor, cap and plugs? You could check for wires arching by using a spray bottle of water. After dark, open the hood, run the engine while misting around the wires. If they are breaking down, you will get a light show /emoticons/[email protected] 2x" width="20" height="20" /> .
Good luck,

>-

I'm with SeaBronc on this.

Troubleshoot it first, don't just go tearing her apart.

I'm guessing it is electrical, becuase that is more common, and easy to troubleshoot, and fix.

Quite possible a tuneup will take care of the miss.

If you think it may be a valve, then do a compression test.

If the compression test comes up clean, then pull DTCs diagnostic trouble codes.

Honestly, I would pull codes before the compression test, just cause it is easier to do.

 

[swampthing]

sounds like it could be the ignition module to me... my f250 did that and it just completely died...put a new module on it and it ran perfect

 

[BLADE262US]

You could pop the distributor cap off and look at the contacts you can do this without taking the wires off you may be suprised and the amount of corosion and possibly moisture under the cap . /emoticons/[email protected] 2x" width="20" height="20" />