Chevrolet Astro Van

[kenmac]

KB, If it runs ok cold then gets rough as it warms , check EGR valve .. If this is a throttle body injection and not the multi-port (not real familiar with multi's but could be same issue), I would also look at the Base of throttle body where the vacuum lines attach for a carbon build up clog that is choking the vacuum off (usually high mileage issue) also possible O2 sensor or Maf sensor, All this is assuming the airfilter is clean and the pcv is good ... a distributor cap could cause a problem but is generally found to be the culprit under load with a miss. Need more info when diagnosing like engine cold/warm when it misses idle/under load, how many miles, last tune-up etc.

Good Luck

Not a real mechanic , but I play one on TV ...

Oh and I own two Astro's 325K & 190K which means nothing...

I'm in agreement ,02 sensor or maf. Of course, there's not much info. to go on.