I've been doing some datalogging since the weather turned colder, and noticed something yesterday that must have escaped my attention:
My Manifold Pressure reads 10-12 volts, depending on how I am driving, using TunerPro RT.
I thought from reading on here that the MAP sensor was a 0-5 volt device?
Any thoughts on the completely out of whack MAP readings?

For what it's worth, my vehicle is a 1993 K1500, 350 Vortec, Edelbrock Performer RPM intake, Holley TBI adapter, stock TB with 61lb injectors running at 20psi, ZZ4 cam, '7427 PCM, $0D code.

Am I imagining things, or should the voltages from the MAP sensor be reading somewhere between 0 and 5 volts? The truck starting running very oddly when the weather changed, which I attributed to possibly a change in the fuel blends.
Now I'm wondering if the MAP sensor is the culprit.

 

What program are you using? Sounds like a definition problem.

 

I'm using TunerPro RT, XDF is 0Dv1_02, bin is a slowly tweaked over the summer BJLH

 

Agree - MAP operates from 5 volt supply rail and its output range is between 0.5 and about 4.8Vdc.

//RF

 

By definition problem, are you referring to the datastream definition file? I can't recall if I downloaded it from the TunerPro site or from Moates.......I will definitely look into that, though.

 

Thanks guys, I found a different datastream definition file and am using it now. It shows the engine idling at 25 KPa, which is pretty good I thought. I read somewhere this morning that the ZZ4 cam has good idle vacuum....now I can tune better I hope, as I have a direct view of what the engine sensors are doing and can apply that to the VE tables.
Appreciate the help!