Gents, thanks for your help. Since my 1st post, I have replaced the fuel filter and put 2 treatments of Lucas fuel cleaner thru the system ( I've driven 300+ miles this week), but I still get a miss when the cars under a load going up hill and now under hard acceleration on the flat. If I let it buck long enough, I can get it to throw a code showing a misfire in cyl 3. So, with the coil pack and spark plugs replaced, I moved onto a possible injector failure. Went to the pick and pull and pulled all 5 for $25.00, replaced #3 and went for a test drive only to have the same miss crop up? Could it be the autolight iridium plugs that I gapped to .028"?