What in the world......Summer VS. Winter

Hey, appreciate any assistance I can get with this....

In winter time, my 90 bronco starts up, rpm's a little high, but then settles down to around 1000 and runs smooth, no problems...

When it warms up (Spring time to summer time) I start my bronco and watch as it revs really high, then stalls within seconds. If I put the foot on the gas I can keep it from stalling immediately, but even after i take it away, the idles jump up and down; withing seconds, it will jump to 2000 rpms, then back down to 700, almost stall, sounding like it is drowning on too much gas and then suddenly rocket back up to 2000rpms, it will do this several time for a few minutes until it seems to warm up a little...

when it jumps up and down, it will usually stall out... If I am lucky, by the 5th or 6th attempt, it will stay started

Any Ideas>?

Probably Air-Related. Something about the humidity of summer choking your ig. system down. Have you ever replaced the O2 sensor?

i think you may be right... However, jsut wanted to see if anyone else has had this problem or has experience with it. If I take the o2sensor out, will probaby end up snapping it to take it out, even if I lube and tap it lol

Would hate to go through that mess not knowing for sure if its going to fix it, but, like I said I can think of nothing else at this point except air leakage which should actually be worse in the winter!!! not worse in the summer

thanks for the input, will probably nudge me enough to replace the o2 sensor ;)

Probably Air-Related. Something about the humidity of summer choking your ig. system down. Have you ever replaced the O2 sensor?