2000 Civic D16Y7 SOHC Automatic

Rebuilt the head due to low compression, compression is good now.

The car is running just fine when I'm driving at road speeds or highway speeds, everything is great. Once I put the car in neutral or park, it rev's itself up to like 3500 and stays there, if i push the gas in it will go higher and stay there too. It also will not let me put the car into park because the engine is revving itself once I stop after driving.

The car is also accelerating itself slightly. If I don't push the gas it will accelerate itself as if I'm holding the pedal at 2,000 rpm. I'm getting engine code P1337, did I miss putting a connector back together, sensor bad, any ideas?

 

Well, did you plug the crankshaft position sensor in? It's behind the lower timing cover right next to the crank gear. Have you double checked mechanical and ignition timing?

I'd double check throttle/cruise cable tension, and all vacuum lines (especially booster). I just don't see how the idle can runaway without the possibility of more air. Maybe check the intake manifold gasket too?

I would also be very careful NOT driving the car as it stands currently. You can damage the torque converter if you're fighting to stop it in gear, or shotgunning it into drive at 3500 rpm...

 

I never unplugged it or touched it so that part is pretty confusing, maybe i bumped it loose or messed up a wire or something? I don't see the sensor, is it behind the crank pulley?

Tension is good, throttle screw adjustments did nothing either way, vacuum lines are all good no leaks, intake manifold seems okay but kind of hard to check that, brand new gasket though.

It idles okay from a cold start for the first minute or until I touch the gas, after it gets warm or I press the gas in it will either A: Rev itself up to 2500-3000 and just sit there revving itself, or B: Rev itself up, then bog, then rev, etc alternating between ~600 RPM and 2500RPM every other second.

 

It kind of sounds it's trying to correct a huge vacuum leak. Try unplugging the idle air control valve and see if that calms the idle down. It's time to check for leaks.

The crankshaft position sensor is behind the lower timing cover against the crank gear. It's possible it may have been damaged or unplugged during your timing belt swap. I just removed mine while I was working on it.

 

Okay I'll give that a try today. Would an unplugged crank sensor do something like this? I saw some posts of people disabling the crank sensor after doing engine swaps to get rid of CELs. I have the cover and belts back on so just wondering whether it's worth the time to take everything apart again to get to the crank sensor or if i should spend my time looking elsewhere