yeah, this is a really weird problem for me.. 1991 plymouth voyager, 184k miles, original everything, 3.1l, 3 speed.

has new cap and rotor--and oil/air filters. about 30k on its tuneup (plugs, few sensors, replaced injectors, etc etc)

and more of a "where to start" thread, than a "i've tried everything" one.

SO, when ya start it, and it's COLD, it does ok, no misses, misfires, etc..

but, i drive to a friends house, which is 1.8 miles away (this is where it gets weird).. and i drop them off and pull out, it starts to 'hunt' for a RPM... it lacks power, but the RPM goes up and down... from nearly stall to slightly above normal. the harder i press the gas, the faster it cycles (untill foot hits the floor, then it pulls out of it till the next light/stop sign). and it will do this all the way back home, or, if i put it in park and idle it.

BUT, (weird, remember?) if i drive it 5 miles... it will never do this. it acts like a normal van. if i drive in 1 mile, it wont do it, it seems to JUST do it when i go that specific distance, and then start it for the return trip.

and, it does NOT misfire, or smoke, or do anythign else, it just makes the RPM go up and down, up and down...

oh, and why does it make a lifter-ticking sound, when it's an over-head cam? what is that? (goes away with good oil changes, or after 15sec-2 minutes of running).

thanks for the advice, ahead of time.