misfire issue.

[byeezy_lb7]

hey guys im trying to get my truck dialed in and truck threw a code for misfire cylinder 7.

the truck falls flat on its face off idle and the injectors clack and sputter and then finally decides to get going.

I used the cts2 monitor to check balance rates and i dont know if my monitor is not working properly but they all say 0.0

any ideas?

motor is fully built, triple turbos with 200 over injectors and dual 10mm cp3 pumps...

thanks.

 

[slowlml]

If they all say 0.0 something is wrong. Whose injectors and tuning?

 

[2004LB7]

I would be looking at the connection right at the injectors. Maybe a loose nut or two

 

[byeezy_lb7]

If they all say 0.0 something is wrong. Whose injectors and tuning?

S&S injectors and pumps and danville tuning

 

[Burn Down]

X2 on a loose injector nut, bad connection.

 

[juddski88]

Did it start doing it after any hard runs or abuse?

 

[KyleC4]

This won’t help your condition but last time I had an lb7 constantly show 0.0 for balance rates the truck had a bad speed sensor on transfer case. When at a stop the tech 2 was showing 1mph being read by ECM.

 

[Bdsankey]

As said above, the truck will not report accurate balance rates if it senses throttle input or vehicle speed. It is also possible that you have a loose nut on an injector causing the issue.

 

[byeezy_lb7]

Did it start doing it after any hard runs or abuse?

It did start doing it after I broke The engine in and started getting on the throttle..

 

[juddski88]

May have lifted an injector, or cup if they aren't threaded... Assuming you don't have an aftermarket head that doesn't use cups. Could be a couple of things, but that's what I would check first. Do a compression test.

 

[byeezy_lb7]

so ive been able to get injector balance rates and I think ive got a bad injector

injector1: -1.3
injector2: -4.1
injector3: -6.7
injector4: 2.6
injector5: 4.0
injector6: -4.7
injector7: -15.0
injector8: -5.1

 

[byeezy_lb7]

Update ... sent out injectors and they replaced whatever needed to be replaced and the balance rates are good but the truck is still puking out smoke and sputtering like it’s getting choked out and wants to die just on normal acceleration from a dead stop. At 3,000 rpm the injectors stop making noise and the turbos spool up and takes off hard... can this be a tuning issue?

 

[juddski88]

I'd be hard pressed to believe that if the engine rpm is varying a lot and the truck acts like it wants to die at idle, that the balance rates are reading correctly.

 

[2004LB7]

Yeah, get us new balance rates and main mm3 readings during the test

 

[byeezy_lb7]

I'd be hard pressed to believe that if the engine rpm is varying a lot and the truck acts like it wants to die at idle, that the balance rates are reading correctly.

Truck doesn’t idle rough. Just sputters when you give it throttle from a dead stop

 

[juddski88]

Who rebuilt the injectors?