94 runs like ignition miss

[Mikey Machine rvellone]

High voltage 4.12v from maf sens ,no reading from egr vac sensor CODES 157 158 335 ,need direction on wire diagram, back probe wire harness for grounds, and typical voltage readings on sensor connections egr vac , air vane temp , tps ect,i no longer have access to mitchel on demand. truck runs ruff stalls , seams to have miss on #4 cyl may be separate issue. no misfire codes. i just registered this morn as member

 

[RonD]

Welcome to TRS

Bookmark this page: https://therangerstation.com/tech_library/index.shtml

Loads of good info there

Scroll down to Electrical diagrams, 1983-1991 applies thru 1994 model years

MAF voltage testing here: https://therangerstation.com/tech_library/CleanMAF.shtml

The 4.0l OHV eats(wears them out fast) spark plugs, try to use Motorcraft or Autolite for longest lasting, NGK work but won't last as ling usually