I replaced crank sensor run fine for a few days then started a missing like water in fuel or running out of gas when under light load if I hold steady it keeps missing. If I let off the gas the get right back on the gas it straighten up and go like it should or I can floor it and will stop acting up. I also have replaced pick up and fuel lines. Did fuel sync it +1 to +3. With snap on scanner I'm not getting any codes with scanner hooked up and driving I lose sync can do a restart by stopping or N drop key off then back on and sync will read ok till it starts to miss again truck has not ever died out just a hard miss like running out fuel it might do this from shift to shift or you go 30 miles before it misses again .I dont think its doing it when in O/D. Only with a load like small hill or slow steady increase in speed. It's just wont keep sync

 

Have you replaced the plenum gasket?
http://www.hughesengines.com/Index/p...p?partid=27091

 

Losing sync is the cause, not the symptom. So, either your 'new' crank sensor is of low quality, or your cam sensor failing, or both.

 

As HeyYou said it might be the "new" crank sensor. What brand was it?