Hey guys, I've got a 1989 Bronco II 4x4. I am about done with the restoration of this wonderful truck but i have a few problems... I got a battery at a salvage yard out of another wrecked bronco that I also got my new door off of. The battery was good b/c I tried it in a few other vehicles I have. But I put it in the bronco and it worked the first day...but overnight and the next day it was completely dead. Nothing would turn over at all. So I charged it and made sure I didn't leave anything on and once again the next day it was completely dead. I have left nothing on and it has done this several times now(at least its not my daily driver...). So what could be causing this?

Second problem is with the engine. When you first start it up it has an extremely rough idle and you have to stay on the gas to get it to keep running. When you take off it has a hesitation in every gear almost. It happens when you let off the gas and push it back again. After a while it gets better but still continues. What would be causing this in the engine. Thank you so much in advance!!!

 

Don't know what to tell you on the dead battery except to install an ampmeter in line with the negative battery terminal and start pulling fuses until the amperage reading drops to around 15-25 milliamps of parasitic draw,

Second question is fuel related, first check pressure, must be 35-45 psi key on engine off, check it at the schrader valve on the left side of the fuel rail, if not ok, pinch off the return line at the fuel rail and key on engine off again and see if it still does not go to 35 psi,if still not suspect heavily the fuel pump, if it does go to 35 psi or higher, then pull vaccum line off of the fuel pressure regulator and uncrimp the return line, cycle the key again and look for fuel coming out of regulator vaccum portor just lower pressure, if it is suspect pressure regulator, if that is ok, then jerk the fuel rail off and pull the injectors out of the rail, and look into the back side of the injector, 2.9's have a problem with the fuel rails deteriorating and rust buildup gets into the backside of the fuel injector filter and resticts gas flow to engine. This is a gas flow problem. Electric1 Hope this helps

 

Got any bad door latches? The monitoring system for these is a pain to deal with. Even with the "door ajar" light off, my rustbuckets monitoring system still put a drain on the system. otherwise the fuse box is a good place to start. good luck

 

About the battery, I agree with doing the ampmeter test.
About the engine, Ford put out a TSB for 1987 and earlier BII's that talks about sludge buildup in the throttle body possibly causing similar symptoms. If your's is needing the be rebuilt, it's possible the throttle body and idle air control valve need to be cleaned.

 

Could be a dead cell. It happened in early Dec 01 on my 89 B II with a Diehard. The BII would crank in the garage which is warm but let it sit outside all day in temps undrer 30 degees and it was dead. The locally bat/parts place checked it ok. With sealed batteries there is no way to check each cell.