My 93 Bronco w/100k mi. has been running rough stalling when backing up voltage fluctuates, voltage also dips and lights dim when stopping at idle.This problem has been a persistent one for about a year.Some times I can see my idle drop to about 500 rpm when coming to a stop, thus lights dimming and almost stalling.Lately with cold weather when first started and put in gear it almost stalls. I did tune up- replaced battery-replaced alternater at 80k when this first started. Also new fuel pump and pressure regulater were put on to correct stalling and a no start problem about at 85kmi .Also, when I check the timing it bounces around and can't get it to stay at 10 degreesBTC. never saw this before.The idle does stay steady when engine is warm and is started up at first when idle is still high but as soon as idle drops to about 700 the timing starts to bounce around.My 89' Bronco never had these problems even with 195k on it. Hope some one can help.PS. I also have what appears to be an oil and maybe anti freeze mixture of gunk that runs out of air filter box down my fender well which I guess is coming from the breather tube? Please help!

 

Doesn't sound good. Do you have the vacuum disconnected from the distributor when you check the timimg? Does the idle fluctuate at the same time the timing is fluctuating?

If there arent any vacuum problems, you probably have a bad timimg chain.

 

there is no vac. on this dist. It does have the spout conn. that is removed when timing is set. I do not see any major idle fluctuations when I check timing. thanks

 

pull codes. i suspect you have a bad TPS and/or IAC valve. what plugs did you use?

 

What would make timing fluctuate? Other than worn timing chain?