Hi all. As some of you know, i'm trying to get my bronco on the road after being in storage for 8 years. I removed the headers, intake and 4brl carb and installed the stock exhaust/intake manifold and 1brl carter yfa feedback carb. I got these from the junkyard. I installed all the emissions components, I got them from the junkyard also. Only things that I did not install are o2 sensor and cat converter. I connected all the cpu harness plugs to the proper components and connected the cpu power lead to the solonoid power side. I connected all the vacuum hoses to where they are supposed to be.
It ran pretty good considering it sat for 8 years. Idle was a little rough but not bad and it was running rich (black smoke from exhaust). Last weekend I drove it around the neighborhood. When driving it was running rough but once the engine got warmed up it ran pretty good.
This weekend I tried starting it and it ran so rough that it would not stay running. When I reved it, it just didn't sound the same as it did the week before. I also noticed that when I turned the engine off, there was real light smoke comming from under the air cleaner. After about 30 seconds the light smoke stoped. Before quiting for the day, I pulled all 6 spark plugs. The plugs were carboned up but not wet. The inside of the tail pipe also coated with dry carbon.
Any ideas what happened to it since it ran good the week before?
I should also add that the battery is about shot. Before this weekend it could sit for a week and still start. This weekend I had to jump start it. The battery seems to have the voltage but not amperage. I know this because the buzzers and headlights are strong.
One thought I had was that the battery is not supplying enough power to the cpu for it to function properly and that is why the engine is running so bad.
Could this be the reason?
Sorry for the long post but i thought I would give as much info as I could.
Thanks.. Bill

<!-- / message --><!-- sig -->

 

Are you running old gas through it?

 

matta, no, I put fresh gas in it about 3 weeks ago. I'm just puzzled that it ran good one week and like crap the next week.
Bill

 

My experience with the battery is if the volt metor in the truck is close to the red or in the red, the bronco would start missing and stall. When it is running what does your metor read. If it is showing in the red, then it is your alt. This could be the reason your battery is bad.

 

You say that you got the carb from the junk yard,did you rebuild it?I wouldn't trust a junk yard carb with out rebuilding it first.Sounds like your getting way to much fuel.

 

That real light smoke coming from under your carb could have been the electric choke control burning up. Since it recently turned cold your choke would automatically close on start up then remain closed after it warmed up.

 

poffutt, the volt meter in my bronco just has lines, no red area. When it is running, the needle is just slightly to the right of the center mark and does not move when I rev the engine. When it was running, I disconnected the battery ground and it kept running. I was told that that is how you find out if the alternator is good. If engine dies then alt. is bad.

glennfordx4, the carb I got from the junkyard has a sticker on it saying it was rebuilt in 1998.

I did find something out today though. Put new fuel filter on, cleaned and gapped the plugs. These 2 things did not solve my problem. So for the heck of it, I started pulling vacuum hoses off of the manifold tree. From the carb float bowl vent, there is a vacuum operated valve on the hose going to the charcoal canister. When I pulled that vacuum hose off, WOW. Idle rpm came up to normal, was idling smooth. Gave it some throttle and it reved right up, just a slight hesitation. Could that valve be stuck open or stuck closed? I'm thinking that if it is stuck open, then the float bowl will be venting all the time and that could have caused it to run crappy. Am I on the right track with my theory?
I'm going to remove that valve tomorrow and see if it is open or closed with no vacuum.
Thanks for your replies.
Bill