stumble at 2700 rpm

[TCluff]

the 03 has a really bad stumble with a backfire, was throwing some codes, replaced the crank position sensor and cleared the codes, now the codes dont return and the tach works like it is supposed to, but the miss stumble backfire with white smoke is still there at 2700 rpm, the engine has 1500 miles on it, i have no boxes or downloaders on the engine, all stock map and wiring harnesses and sensors wtf truck runs great untill then, the injectors are industrial inj but were brand new modifieds, 63 litre and still only running on one cp-3, just trying to get some miles on it before dumping alot of fuel to a fresh rebuild...

 

[lubeguy]

ck fuel supply to engine. .

 

[TCluff]

ck fuel supply to engine. .

48 psi at the inlet of the cp-3, the stumble occured again today at a lower rpm, around 1500,

 

[trainhorndodge]

Try turning your lift pump down to about 22 psi. Unless you have a modified cp3 that needs the pressure most cp3's will act up higher than 25psi. You don't need pressure just volume.