BroncoII4x4.com

Well I have an '89 Bronco II 2.9 Auto 4wd... Heres the problems that I have... First off its really getting slower after 25mph-35mph and sluggish and missing like crazy! And I mean slower like lack of power. Now when its at idle its not to bad, you can floor it and sounds like its running good and on all cylinders, but when you actually drive it, thats when it starts spitting and missing like. Now this is what I have changed and all new parts.... Cap/rotor, plugs, wires, air filter, fuel filter, oil/filter, tranny fluid/filter, battery, and battery cables... And it seems like its getting worst and worst, which I dont drive it everyday only when I need too, its my hunting/winter truck. But would be nice to get it running right plus it seems like its sucking down alot more fuel, but I have checked and pulled all the spark plugs and they are all burning the same and good, and the exhaust isnt smokey or doesnt smell like unburned fuel either.... Second problem is after she sits for a couple days the battery is complety drained and have to jump it all the time, which I have no idea what is draining the battery down.... And thats about it, if anybody out there that has had the same problems or know what to do next any help would be great! Thanks for your time and reading this! Jim

Nobody has had any of these problems??? Or have any thoughts or comments what could be wrong???

battery drain could be a short somewhere or a ground that isn't plugged in. You could even have something that is staying on, but perhaps you can't tell. Like a dome light with the bulb missing...you can't tell it's on, but it is and that'll drain ur battery.

as far as everything else...I was goin to suggest to check your timing, but you said it revs fine while in N...so I'm not sure. Perhaps a fuel pump malfunction or injector issue??? I'm assuming it's fuel injected and just spit-balling here.

Get the codes run on it, if you can't find somewhere to do it, buy a code reader. You can get them for the OBD 1 for about $30 at most parts stores, believe me, it will save you a lot in the end. You B2 has about a dozen sensors, half of them could be creating your problem.
When you change anything that has to do with the ECM, (sensors,timing) disconnect the battery for a half hour or so to clear the memory in the ECM, then drive twenty or more miles before you make any decisions.

Ray

if anyone got any suggestions im having nearly the exact same issues with my 89 b2 2.9.

On my '88 2.9 I had what looks to be the same problems, it would rev fine, but under load it did the bucking bronco thing. One item that NEVER showed up on the scans was the O2 sensor. Changed it out and all was fine.

coil? i would make sure it's not a fuel problem 1st. hook a fuel pressure gauge to it and drive it.