160,000 plus miles. New Cap, Rotor, Plugs and Plug Wires. Starts and idles always, won't rev past 2-3 krpm. Feels like it is starving for fuel or air. Old plugs did not look very worn or dirty.

 

Any other codes besides P1399? This code indicates multiple variable misfires.

See my suggestions for vacuum checks in post "Loses all power at around 4000 rpms, no codes at all".

You need to first determine if misses are ignition or fuel related. Likely fuel related; intake air filter restriction, fuel pressure, or massive intake air leak (check all vacuum lines and components).

good luck

 

Vacuum check was a good suggestion, TexasHonda. https://www.hondaaccordforum.com/for...lies/smile.gif Before I got the vacuum gauge I tried spraying carb cleaner in the intake as I revved the engine: no improvement. I thought that pointed to something other than a fuel or intake air leak problem. Once I got the vacuum gauge I checked the wife's 2000 accord against another good running 1999 accord. 99 accord showed 20 inches at idle and revving the engine made the needle dip momentarily before steadying at 20 or so. Our '00 idles at 20 but drops off steadily as I rev it: 18 at 1500 rpm, pretty steadily drop to 5 inches at 3500 rpm. I also heard what sounded like rattling loose pieces of converter innards as I revved it. The entire exhaust system (except for the cat) was replaced about a year ago. The cat is original as far as I know. That is about to change.

 

If you don't have 12V, then check whether AC relay is receiving a ground supply from ECU (voltage goes from 12V to near-zero volts at red/blu on AC relay) when AC is commanded on.

If not, the ECU is missing a ground signal input from red/wht wire which connects AC diode to AC pressure switch-AC thermostat-AC Switch. If any of these three are open, no ground signal will go to ECM and ECM will deny ground to AC compressor relay to actuate compressor.

You have checked AC pressure switch and AC thermostat. If you have 12V on red/wht wire at AC pressure switch diode is not open. This would leave the AC switch as likely open preventing AC from working.

Check Blu/Red wire at AC thermostat for ground w/ blower switch on fan speed 1-4. It should show zero ohm resistance to ground. If not, the AC switch is open.

good luck