I have a 2004 duramax every now and then u crank it up and take off it acts like it gets on a rev limiter at 1500 rims if u floor it runs bads then dies someone said might be the ficum we checked all the wiring for cuts all is good

 

how many miles on the rig? original CP3?

 

200,000 and yes

 

what about injectors? sounds like a weak CP3 or High return rate on a few injectors but its hard to know without hands on with it

 

Brand new injectors

 

might want to get someone with a TECH 2 or a dealership to check your CP3 command max psi and see what she is putting out