1987 ford bronco 2 running rough

tacoterry · 05-23-2009, 08:16 PM

I just recently purchased an 87 bronco 2 for $400. BOdy is good shape, thought what a buy. Seemed to run decent. Here lately though after driving about 5 or 6 miles it tends to start bogging down and barely gets to 45 mph, especially when going up hills, and seems to have a little shake in it. I have changed the plugs, wires, distributor cap, rotor button, new muffler, catalytic converters, and fuel filters. Still the same thing is happening. ANyone have any suggestions. Thanks

BroncoJoe19 · 05-24-2009, 05:47 AM

Check your battery condition, make sure the alternator is charging, check battery connections, fuel pressure at the rail, should be I'm guessing about 35psi

and if all that is good, then pull diagnostic codes.

Pull Diagnostic Trouble Codes (DTCs) From your onboard computer.
Your engine and transmission are computer controlled.
The computer uses sensors to tell it a number of different things and it controls actuators that push or pull mechanical levers (kinda). If one or more sensors aren't working properly, the computer goes "blind" and doesn't know what to do. If the computer can "see" but one of the actuators is broken and therefore can't follow the commands of the computer; the engine won't run correctly. The computer is preprogrammed with set values for each of its sensors, and each of its actuators. It will run a self check of all systems, like the space shuttle; it will compare its set value(s) to the value(s) it recieves from its sensors, and actuators. If any sensor or acutator is out of the "normal" range the computer will generate a "code." It will generate some codes on the fly, and others will be stored while you are driving. There is a simple method to "pull codes" out of the computer for one to use for diagnostic purposes.

Earlier versions of On Board Diagnostics OBD 1983-1995 can flash the error code to the dash board and can be pulled in one's driveway without any special tools.
Later versions of On Board Diagnostics OBDII some 1995, and pretty much all 1996 and newer, require one to use a code reader or scanner tool.

Some auto parts stores will scan your engine codes for FREE, you may want to call around. Some will scan OBDII but not the older (prior to 1996) OBD systems.

SO here you go...
How to scan FORD on board Diagnostic Trouble Codes (DTCs) in your driveway
Howto Pull Codes 1983-1995 Broncos, Mustang, F series Trucks, Econolines, 302, 351 and more

tacoterry · 05-24-2009, 04:43 PM

I am looking for the plugs right where you said to find them. I am not seeing either of them. ANy other place they might be??

BroncoJoe19 · 05-24-2009, 07:13 PM

I don't know exactly where they are in a B2, but they might not be just hanging freely, out in the open. They may also be plugged into a protective cap. On the full size bronco, and f150s they are located on the battery side, clipped into a cap, that is mounted to a holder that also holds the EEC relay, and the Fuel pump relay.
I hope that helps.

blue beast · 05-28-2009, 06:17 AM

If it has sat for awhile the fuel that was in it is starting to go bad! Not to mention if it was left near empty it was condensing water. First double dose it with 2 bottles of heet and one bottle of iso heet on whatever is in the tank, Drive it at least 10 miles then fill it with low octane gas. Gas over 90 days old is starting to rise in octane points and it will have a tough time burning it and the water will be partially or totally blocking small openings in the fuel rail,lines, filter etc.

mustangfan18 · 06-23-2009, 03:55 PM

You should also use some Gumout to make sure the cylinders are firing at full capacity and to make sure the old gas isn't blocking off the flow somewhere like the fuel pump.

1 wrench · 11-02-2009, 04:02 PM

Quote:

Originally Posted by tacoterry

I just recently purchased an 87 bronco 2 for $400. BOdy is good shape, thought what a buy. Seemed to run decent. Here lately though after driving about 5 or 6 miles it tends to start bogging down and barely gets to 45 mph, especially when going up hills, and seems to have a little shake in it. I have changed the plugs, wires, distributor cap, rotor button, new muffler, catalytic converters, and fuel filters. Still the same thing is happening. ANyone have any suggestions. Thanks

Two things come to mind. The first is the ignition control module located behind the distributor ( on the back of the distributor) ( its a little rectangular shaped plastic slim box attached with two 5.5 mm screws. Take it off and get it tested at auto zone or another parts store. The other thing that comes to mind is the temperature control sensor located behind the top radiator hose. Its kind of hidden. Disconnect negative battery terminal, remove top radiator hose (only if the engine is cool so you don't burn yourself). Remove thermostat housing, remove connecting wire from top of sensor, use 1 1/8th deep well socket to remove sensor. Put thread tape on new sensor, and reinstall.
Good Luck
1 Wrench