[280xtz]

On a 78 280: I adjust the valves to the cam card spec (.012 hot). This was done with the motor hot (duh), and the actuating part of each lobe straight up (valve fully closed). While in the cover I found a threaded plug which installs in the rear end of the cam (internal oiled) was very loose, and tightened it. The problem is that now with the hose for the cam cover (vent) connected the car idles at about 500, same if you block off the hose end, no effect if you block the cam cover vent. Also the car seems to be loading up (rich) when reved. All plugs seem to be fireing and the timing is at 12 degrees adv.I have changed nothing but the valves to create the problem.

Thanks in advance,
Cliff

 

[Zuber]

Hmm. One thing I can suggest is that you adjust your idle back up to 800, and see if you still have the loading problem.

Your adjustment of the valves may have changed the idle, depending on how they were when you started (were any of the tolerances too tight? Too loose? You do know that the intake and exhaust valves are adjusted to different specs, right? You only mentioned one. How did you get all the valves adjusted with the engine at the same temp? That is why I do them cold. At least they are consistent. By the way, how do the valves sound now?

I don't think the loose cam oiling port contributed to the problem. Fix your idle, and see if you still have a problem.