Have a 1999 Prelude Auto with a very unique issue. Here's the list of symptoms:

Rev Limiter at 6,500
VTEC Still Works
No Check Engine Lights, but the CEL is known to work.
Speedometer Still Works
The car appropriately skips VTEC when it's cold, but the rev limiter is at 6,500 regardless of engine temp.
The car is bone stock, no aftermarket engine management.
Coolant and oil levels are fine, coolant recently bled.

There was a D-series guy who had a similar issue, and he replaced coolant sensors and thermostat which fixed it, but because my car still skips VTEC when it's cold, but allows it when it's warm, I doubt this is the issue.

There was a Prelude guy who said it went away when he switched to OBD1, he had a manual transmission. I've learned that OBD1 doesn't use secondary O2 sensors, CKF sensor and knock sensors. Is it possible any of these are the culprit?

I have what seems like a bad LMA that sporadically causes loud ticking around the driver's side of the engine bay. Is it possible the LMA tick is setting off the knock sensor and this is what's keeping me from going over 6,500? The tick seems to come and go, usually brought on by hard or long drives; maybe it actually is detonation? See videos below:

Here's a video of when it's bad:
http://s1136.photobucket.com/albums/...-29-57_295.mp4

Here's one of when it's not so bad:
http://s1136.photobucket.com/albums/...-58-29_290.mp4


Ask any clarifying questions you need. Any help or input would be deeply appreciated, this one has me stumped.


Thanks!

(Sorry, mods, for posting in two seperate sections).

 

Bumping this once before my appointment with my mechanic.

Current theory is his part supplier may have sent him the wrong belt that was one tooth short. Here's some pics of the belt, which seems to be walking itself off the cam pulleys and grinding itself to dust.