i've had this problem with my 89 for a few years now. it starts and runs fine, but developes a miss at warm idle. almost like it "loads up". on warm starts, it will turn over, start, them stumble and almost die. the vacuum gauge that I installed on my dash shows the vac start at 20, then bounce around at 15. almost every sensor is new, no trouble codes, I just put in that new engne, and replaced the fuel regulator and injectors. any ideas would help. could it be the pickup coil in the dizzy?