Need Help Understanding Code 33 (High MAP)

[jmgtp]

Stock 3500 location, right on top on intake manifold.

[robertisaar]

i ask only due to wondering if it's similar to the LH0 ported vacuum setup... in that situation, the CCP solenoid will only recieve manifold vacuum when the throttle is opened ~5% or so, but before that it has atmospheric pressure... was thinking maybe something was working in reverse of that here.

[jmgtp]

Forgot to mention that I also verified the external crank trigger is set at 0 degrees.
I'm pulling valve covers tonight and inspecting rockers/springs. I can't see it being a rocker/spring because it idle smooth, quiet and with good vacuum but I'm out of things to check.

After that I'll do a compression test. If that shows nothing I'll run a mechanical vacuum gauge and tape it to the windshield to verify manifold vacuum against the map sensor reading.

[jmgtp]

Wanted to update with some progress. Ben has continued to revise bins for me based on the datalogs I send him. The car is becoming MUCH more driveable and I can't thank Ben enough. Also, as of the last 2 bins that he has worked on I no longer have code 33! The manifold vacuum I believe still looks a bit low at part throttle but the car is driving much better.