reguardless of RPM if I hold the throttle in any one place the car just surges up and down about 500rpm. its a very consistent surge.
At idle in neutral it will idle smooth for about 15 seconds then shoot up by about 500 rpm then the car will stumble until it dies.
as soon as I put it in gear it will stumble at 375RPM with the IAC all the way open.
The strange thing is the car drives okay when its moving and actually has pretty good blm data.
I am completely out of ideas.
I have changed the commanded idle all over the place, unpluged the IAC, unpluged the MAP, changed the SYNCH ASYNCH changeover, flattened the timing all around idle,borrowed map from car next to me that was idling, changed injectors, switched map sensors, closed loop and open loop idle. pretty much everything I can think of.
The car is the one in the sig below. I am using a 7747ecm.
could the size of the cam be directly causing all of these problems?

I know its a pretty general open ended question, but
ANY suggestions would be great. Just to point me in the right
direction.
thanks!!