Finally got around to changing ECU. No help, Still surges under AC load.
It does run fine at times, but not for very long with AC on. Runs fine without AC. Here is what I did to save you from reading all the above, New FIV currently blocked off. New and IACV. EGR valve holds vacuum, coolant temperature sensor working properly, coolant level fine, no air. Air boost diaphragms are bad, but have air boost valve blocked off for now. No vacuum leaks, and no codes. I seems to definitely be input related and not a vacuum leak. I can tell the problem is there at times because idle is high and breaking takes more effort. When that happens, (the AC is on) I put car in neutral as I decelerate, when car speed reaches zero, tachometer creeps up to 2100, when computer cuts off fuel and idle lowers and surge begins, sometimes I can shut AC off and problem goes away after ten to fifteen seconds, other times I have to drive, a very short distance with AC off and problem goes away. I noticed the following: at times as idle starts to creep up, I can hear a click behind the center console, which sounds like a relay, and idle immediately returns to normal. If I do not hear the click, surge begins. I checked the AC clutch in relation to the problem, sometimes AC clutch is engaged and no problem. Does anyone know if Honda uses switches on the AC compressor 9 or somewhere else in the AC circuit) that somehow feeds the ECU for idle? It is not as straight forward as AC on †idle problem present, - AC off problem gone. Sorry for the long post, but only way I could quickly get you to where I am.
Tuesday, October 16th, 2018 AT 4:31 PM