I have a 2003 Dodge Ram Slt Quad 4x4 w/5.7. Truck was running great then all of a sudden while driving it stalled. Pulled over, now it barely runs??? Vacuum test shows 4" vacuum at idle and 15-20 at 2000 rpm. It only throws a a 300 code???
We have pulled intake manifold off, seams OK. Compression test all within 15 lbs. Pulled valve covers off springs ok? Wires and loom, OK. Fresh factory plugs, OK.

Truck has 80,000 (Bought New) and has always run Perfect?

Help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Bill

 

I would start with checking the fuel pressure. If good, then perhaps the crank position sensor.

 

How about timing chain jumping a tooth?

 

Wow you guys really ripped it apart. I'm willing to bet my last dollar it's the fuel pump.

 

Yep, both heads coming off for valve jobs and springs, probably new rods, timing chain and water pump as well. With the new paint job...hope it goes another 50 - 70k???