Nytro97

This all started with just the P1078 code.The IMRC. (malfunction high RPM) With just an engine light on and 2002 CRV ran perfectly.

Now the idle surges back and forth between 500 to 1300 RPM's

I removed the manifold and pulled the runner valves and inspected. It all looked good except the bushing from the end of the rotary valve was stuck in the bottom of the manifold.
I reassembled and replaced the IMR solenoid. I was not getting the P1078 code anymore but now getting the P0505, P1077 and P1505.
Not feeling right about the stuck bushing in the bottom of the manifold, from the end of the runners. I found a complete new sealed in box Honda manifold with rotary valve for $200.00 and installed it. (just ruling out any possible issues.)

I have checked all the vacuum hoses and don't see any problems. With the intake boot off I block the IAC port in the throttle body with my thumb and it idles perfectly. Also when I cover the throttle body the engine will stall.

What could have changed ?? Is there something I missed.

Thanks for any help,

Tom

Nytro97

Well I took it apart again ...double checked all hoses and replaced the PVC valve just in case. I removed the idle air control valve from the throttle body and cleaned it with carb cleaner.

Reassembled and started it up , engine was running a little rough but smoothed out and idled good. Added a little anti freeze, finished installing the rest of the plastic top and bottom on the nose etc.

Now I have a rotten brake line leaking down where it goes under in front of the fire wall. A terrible spot.

Hour later started the car again to check and it is surging again....I have had enough. I must be a bad idle control valve.

Nytro97

Well to follow up,
I repaired the bad brake lines...Could get to them by removing the air cleaner box. Installed a new Idle air control valve and The idle is perfect. Cleared the codes and hope the engine light stays off.