So my 5.3 has issues starting and I just notice that with the engine OFF the MAP sensor is reading 97kPa. I have no codes and I triple checked my wiring and its good. Could this be a bad MAP sensor? What is it supposed to read with the engine off? I figured 0. Heck I even unplugged it and hptuners scanner is still showing 10kPa. Any ideas? Thanks in advance for any help.

 

97 is right... its opposite from what you think.. 97 is the reading when theres no Vacuum in the intake..
should be around 40ish at idle.

 

Well, Thanks. I guess I'm going to have to look else where for my starting issues. It will eventually start and sometimes run good, sometimes run like caca.

 

is it a stock cam & stock tune?

 

I figured it out...When I moved the pcm I forgot to hook up the ground wire for my coils on bank 2. Dumb a** on my part for not checking for spark first..haha "but it was running before I moved the computer..." <- stupid...