Originally posted by DennyW
I think you are a little confused on the MAP sensor. Do you understand the job and what it's supposed to do ?
I have spent the last 20 years working as a G.M. dealership tune-up and drive-ability specialist, so yes I know what a map sensor is there for and how it works. That's the reason the engine runs at all. Having to trim off the vacuum is one of the reasons I think the edelbrock EFI program doesn't match the camshaft.
My readings, vacuum and rpm along with the lack of lope in the idle is the reason I suspect the cam may be more stock than one with 230 to 240 duration. Having 20" of vacuum at 800 or so rpm with out a lope just makes me wonder. I am trying to gather information outside the engine to make a decision on my next move. I think the cam just may be different than the one the EFI is calibrated for what do you gents think???