Morning
94 940 NA Bosch, 243,876 miles. Random skip/miss at idle only. Tach dips slightly when skip is felt from the normal 750 to 550'ish then pops right back to 750. Real quick like. Truly feels like an ignition related miss. Fuel consumption normal. Runs like a champ at 75-80mph on highway. In the last week I have R/R'd: Cap,rotor,plugs,wires. Cleaned grounds. Checked for air/vacuum leaks, found a slight leak at front flange of catalytic converter but seems minor. Removed Throttle body, cleaned and adjusted same and replaced. Checked codes, none in 2 or 6. Had state emissions testing performed and passed easily on all measures.
Tonight I am going to pull new cap and take a peak inside and make sure mositure didnt intrude after last storm. I have a spare known good power stage, and will r/r that to eliminate that piece. CPS looks good and isnt throwing codes, but it has been in there at least since I have owned it(171,897 miles). I swapped the IAC with the known good from my other 940. I would mention that connection to the IAC seems somewhat suspect as I have gotten codes in the past for IAC signal missing. Not sure if a crappy connection at that juncture could produce such a sudden and minor dip....Would anyone care to add items to check?