Here's the deal:
71E; stock B-20E engine and FI, Pet electronic ignition installed two years ago, and running great...'til just recently. Also installed A/C solenoid switch to keep idle up when operating A/C. Has been working good for past year. The car is an "every-other-day" driver, except if it's raining. For past few weeks, have noticed a momentary (microsecond in length) hiccup every now and then. Hiccup occurs only when throttle is relaxed, and not under acceleration. When cruising along at 45-50 mph, uphill, with throttle pressure, it will not hiccup; at same speed, downhill, letting off accel just enough to maintain speed, it will hiccup once or twice in a 30 second period, then not again for awhile -- then it's OK. Does not miss or hiccup when revving; idle seems a bit rougher than it used to be, but does not miss at constant idle. Any ideas or suggestions?
Roy
71E