Fuel pressure should be 45 to 50 pounds at idle. It can cause rough idle if it is not high enough, but usually, it should starve for fuel at highway speeds. But a quick and easy check to eliminate it.

I would also check all the grounds. Battery to fender, battery to fra, and then engine ground to battery. Also pass side head to firewall.

 

Checked the fuel pressure. Its at 50 idleing. Also checked grounds. Was missing battery to frame. Made a 4 gauge wire and ran from battery to frame and no change. Still idles from 400 to 1200 and sometimes dies and still spark knocking after half throttle. Im about to give up on this piece

 

That still sounds like a vacuum leak... Check the EVAP system for bad hoses. Investigate the rest of the vacuum lines as well. Cruise, 4x4 engagement, and the little elbow for the MAP sensor would be likely culprits.

 

So getting a can of starting fluid and dousing vaccum lines and everything and seeing if it idles way up should work then right?

 

But carefully. I always hesitate to tell someone this in case they catch the engne bay on fire.

 

Alright lol ill try that tom when I get home from work. Ill up grade to full coverage first also jk

 

Use carb cleaner, or Brake Cleaner. Not quite so combustible.

 

+1. And have someone in the cab to shut it down if necessary!

 

Not to mention a fire extinguisher being handy......

 

I will thanks guys