2007 c15 accert blowing white smoke

Never mind

 

Guessing..fuel injector..broken rocker..wore out cam. Hopefully something more minor. May have to see engine doctor. Could be wiring. As in to injector.

 

li

the shaking and smoke under load is likely an injector with a sticking actuator or armature spring. you'll need a dyno to diagnose if its intermittent. if its pretty regular take someone with ET for a drive so they can do cut out test to diagnose which one needs replacing.

the general low power can be many things. boost leaks, low fuel pressure, blocked air filters etc etc.

start with those basics

 

boost pressure and air volume are different. even with sizeable charge air system leaks it will still make the nominal boost pressure. but it will be delayed in doing so which will delay rack increase, especially on an ACERT. it will also push a percentage of air volume to atmosphere instead of the engine which will cause low power.

you'd be surprised how many boost leaks of decent proportion are found on trucks still making normal pressure during operation.

more so on an ACERT but applicable to all cats.... boost leaks will cause higher cylinder temps, less power and more fuel burn

I fit a blanking plate behind the intake to the head and use a silicon adapter to join to the compressor housing where the intake pipe goes on. with a regulator I put 40psi into the CAC system and listen for leaks

 

Remember that air-air don't cause it to shake. Or smoke. Ecm cuts back fuel if low boost. It will on older mechanical though.

 

with ACERT for emissions they wont increase rack position (add fuel) without the required boost pressure increase first. pre ACERT is not as bad, but similar in operation. 0.01 of 1 single psi boost pressure will alter the rack position and fuel delivered.

its catch 22 as fuel will help build boost but with ACERT its a pretty fine tolerance.

with boost leaks it will delay the off throttle building of boost with leaks and in turn delay the rack increase making it feel lazy and not as responsive. then it gets beaten on all day to try and get it to go.

with boost leaks you're still using the same fuel as without once you're up to speed as fueling is referenced off boost pressure not air volume. but a percentage of your charge air is going to atmosphere through the leaks instead of in the cylinder. that means the combustion isn't as efficient with the lack of air and makes less power, meaning you're on the peddle for longer.

low fuel pressure and boost leaks are the main cause of low power and fuel burn increase.

you should have 90psi low idle fuel pressure and 105-110 psi high idle. if not then confirm your filters aren't plugged and fit a 3049385 check valve (to filter housing) and 3394983 spring kit (to transfer pump)
to bring it up