Vtec engages and I hear a weird metal to metal noise. Almost like a valve barley hitting the piston but it isnt constant enough. It also feels weak at open throttle and the intake sounds like its going in and out of vtec. The selinoid is staying open, oil pressure is steady, timing is right,and im N/A. I just got the head back from the machine shop. If they happend to have left one of the lock up pins out of the rocker arm assembly, could that cause this effect? Remember it feels like i only have vtec on a few of the cylinders. I will be pulling the head apart this weekend but if anyone has run into this problem before please let me know what it was so i can collect the extra parts before i pull it all apart. Its a dohc head. Thanks

 

have you upped compression.......cause that metal to metal sounding noise(kinda like a valve is really loose) is usually detonation, my car was detonating like a champ, just add some fuel, and yes if they left one of the pins out it would do that, but you would notice it alot more than you do since that shit would be bouncing around even when vtec isnt engaged........

 

No its a stock gsr block,b16 head. At first i thought it would be detonation too but the plugs are fine. Its alittle loud to be detonation, def. metal hitting metal somewhere.

 

Is you timing belt off a tooth or two?

 

One of the lock up pins were missing out of one of the rocker arms. Thanks for the ideas!

 

Holy shit, that's a little bit of an oversight.. Did they leave any tools in there?

 

who put the head on?.....

 

Machine shop put the rocker arm assymblys back in after installing new valve guides. Its very easy to have one of those pins to fall out and not notice it if you dont work on vtec heads all day. I missed it the first time I checked, went over it again and noticed it missing. Hey Fabrik8, the ecu chip works great