Engine code U. 220,000 miles. Out of blue I have a really high idle. I am a retired computer guy and have tried to service my own cars. Idle 1800, after clear 2200.
I have a Bosch 1150. I ran some tests to see if I could tell but no codes had been set. Later it did code P1506, P1504. IAC has not effected idle plugged or unplugged.
I replaced the pcv valve and visually looked at hoses and sprayed looking for leaks. Then I cleaned mass air flow, throttle body with the correct sprays. I reset the codes which was a mistake. Unplugged battery while I cleaned and disconnected.
I took a drive and made recording of four tests, drive test was not complete so I still I have drive code.
I wondered if something could be interfering, tested the charging system on a new Costco battery
DLC KOEO 11.7
CRANKING VOLTS 7.2
DLC KOER 13.7
Best I can tell the alternator is crapping out and must be effecting IAC. I ordered a alternator. Snow storm coming did not check with load or check the resistance or the voltage on my IAC. Or I did not check the voltage at the alternator or going to the IAC.
Any suggestions, insights, tips? I will pick it up after the storm and I install the alternator