You only have 10" of vacuum at idle? That ain't right. You should see at least 17"..... You have a pretty significant vacuum leak somewhere.

 

That's the reading from the manifold *absolute* pressure sensor, not a direct vacuum reading. MAP should read 29ish with the engine off, so there is about 19" of vacuum. Looks ok to me.

 

You are quite right. Thanks for the correction.

 

Something is telling the truck it has more fuel than it does or that it has less air than it does. The only sensor you have not replaced yet that influences this is the MAP sensor. Since you were messing with vacuum lines make sure that it is routed so that none of the check valves are blocking the vacuum signal first but it sounds like you map sensor could be starting to fail. Other possibility is you have a new bad sensor. Also check all your harness's, make sure no critters thought the wires looked tasty..................

 

ok question, is the check valves directional? And if so how do I know which way they go?

 

Yes they are. Should be an arrow on them pointing in the direction of flow. If there isn't, just blow thru it, that'll tell ya real quick.

 

They are directional but the vacuum feed to the map sensor should be unobstructed by any check valve no matter the direction of flow.

 

Check valves are for the line going to the reservoir/hvac controls.
When it won't start you need to see what's missing, Fuel of spark.