wkmania

Have been wrestling with this starting issue on the Jeep. It cranks but doesn't turn over. The story so far.

• I removed the air intake and sprayed starting fluid directly into the throttle body and it starts up, with this I concluded that air and spark were fine and that this is a fuel issue.
  
• I removed the fuel line going to the fuel rail and put a can there to see if fuel would come out of the line when I either turned on or cranked the engine and no fuel came out of the line. This further seems to support the idea that the issue is in fuel delivery to the rails and not something like the injectors not firing due to computer issues.
  
• I then removed the electrical connector going to the fuel pump and tested the voltage when the key was turned to the on position and noticed that the voltage did go up to 12v however the only odd thing I noticed was that it hit 12v for just a second instead of the 3 seconds I was expecting.
  
• I moved forward with this anyways and decided to replace the fuel pump after lowering out the tank, however even with the new fuel pump the engine doesn't seem to turn over.
  

At this point I am wondering if the lack of fuel is caused not due to the fuel pump but due to something else, but what could it be? I am also thinking of hooking up a 12 v power supply ( the battery) directly to the old fuel pump to see if it turns.

Hemiwk92

Any luck on this?

wkmania

Yes, I figured this out the wrong way but I did figure this out.

tldr; turned out to be the fuel pump relay.

long version - I had initially tested the voltage at the terminals coming into the fuel pump, the WK harness can be disconnected at a point where the wiring then heads over the fuel tank, I tested with a voltmeter at this point and saw the requisite voltage when the key got turned on however the pump would not turn on, with this I assumed that the issue lay with the fuel pump and I ended up lowering the tank and replacing the pump. However that did not fix it either, turned out that the relay must hold the voltage for 3 seconds otherwise there isnt enough time for the fuel pump to start and run. once i replaced the relay it worked like a charm. Hope this helps.