So the 318 is running! No magnum heads, just mid 80’s heads with a quick lapping of the valves.

For a refresher, it’s a stock motor freshened up. New rings, bearings, etc.
New Comp Cam XE250H (.432/.444 lift; 206/212 duration @ .050)
Edelbrock 1406 (600 CFM) carb.

I am very happy with how it drives. It pulls a lot harder at WOT, it sounds more mellow (yet doesn’t seem like it’s fighting itself). It still warms up quickly under driving conditions due to the lean carb (I will change jets soon) and 190 degree thermostat, but it seems to be doing ok so far. There is a small surge at steady RPM’s while driving though, but you have to look for it to really notice it.

So now, I have a question about the poor idling quality.

It runs great in Park or Neutral, but when I put it in gear, it runs rough or dies. Sometimes the RPM’s will drop and it will sputter for a bit then die.

15 lbs of vacuum at idle. In gear it drops to 12 lbs. It holds steady until it sputters and dies. In “Park” the needle doesn’t even move. The initial timing is 16 degrees BTDC, and I am unsure of total at this time because my damper is not marked. It does increase with engine RPM though, I made sure of that.

I also noticed the PCV valve was making noise, almost like a quiet tin can rattle or something. When I pinch the line or plug it off, the sound goes away. I tried 3 different valves until I put the original one back on.

Another thing I noticed: I disconnected the PCV line so it was just sucking air. It is a constant sucking, no pulsing noted.

However, the RPM’s increased quite a bit. I turned the throttle screw down and it seemed to run better at idle. I put it in gear and it didn’t die as quickly. It ran much better.

The idle screws are turned 1-1/2 turns out. This seems to be where it likes it the best right now.

So….I have another 1406 carb I can try running to see if the carb is the problem.

I know my carb is jetted lean, but this should have nothing to do with the idle problem. I sprayed out the idle screw holes with carb cleaner, but I didn’t see much change.

Any ideas where to start here?

Thanks guys!

Eightlitermopar