[67ragtp]

Heres my scenario, Im driving out to pocono for the good guys event early this morning its about 50 degrees out might have been in the 40s never had this car out for a long haul. just local cruises, but it was tuned by a professional tuner on a dyno with a eddy brake and suppose to be dialed in for cruise/WOT/cold start and all that stuff. Its a 427 mitchell sb with 42 lb injectors on a sigle plane with a fairly mild hyd flat tappet. So the 100 mile cruise up there although cold was flawless not a hicup. Noticed that my water temps were barely 165(big RD radiator and cold out).

The ride home its a bit warmer but not much maybe 55 degrees but the water temp at times would be between 165 and 180 after about 50 miles at between 2000 an 2300 rpm cruising in 5 th gear at around 70mph it would periodically stumble. It was like a jerk in the engine some times heavy and sometimes light. Like a hiccup. So Ive got the wife in the passenger seat and we pull out the lap top and plug it in. As the hiccups are occuring every so often we are monitoring were the foot ball is in the VE fuel table. So we increase those numbers from 34 to 36 around 52kpa then we go over to the A/F ratio map and change those numbers from 14.7 to 14.3. Im thinking Im adding a bit more fuel and this is a lean stumble but it really doesn't do anything with these changes. I remember getting this type of stumble on a very hot day about a year ago when I jumped on a higway. My wife said the actual a/f ratio was averaging 14.5 to 14.7 with moments as low as 13.8 and as high as a 15

Could my under hood temps be causing this and how do you tune it out? I just have a feeling the hotter it is outside the worse this will be, any suggestions?

Thanks Rich