i've got a 1990 pontiac transport. it runs very nicely for the first
15-20 minutes. after that period, it won't downshift when coming to a red light (can't we just do away with red lights?). when braking for the light, i can feel that it's not going to down shift, so i put it into neutral, and it idles fine at the light. i put it back into drive and have to floor it hard while shifting it to keep it from stalling out because it's in a high gear. if i leave it sit for a while it seems to be ok again for another 15-20 minutes.i haven't taken it anywhere to have it looked over, and really dread taking it to a trans shop to see if that's it. a couple of potentially unrelated points. the van doesn't like to start when its wet outside. just after or during a good rain. sometimes i notice a gas smell from under the hood. when it's wet outside, i can put a hair dryer under the hood and eventually after a while it'll start. still has the downshift problem though.
any ideas on why this van might not be downshifting properly? hopefully some electronic parts, or somesuch outside of the transmission?