C15 fuel consumption problem

[Khein]

Im having a problem in a client Peterbilt with a CAT C15 engine.
A week ago it came to our workshop for a service and we check injectors, variable valve actuator and engine brake and everithing was ok. The only thing we change because it was not working is the variable valve actuator pressure sensor.
Now the truck has increase in a 50% the fuel consumption and obviously the client is complaining about it.

Anyone has a clue what could be the problem?

[dlogi]

I everything else tight in the charge air system? And the check ingine light is off now? I have had cases where the IVAs didn't register as not functioning but when I ran the cut out I didn't here them click. Once I changed them the boost went up to 50psi where it shoud be. I have also had issues where the VVA pressure sensor wire was bad or the pins in the plug so even after I changed the sensor a little while later we had the same problem. I have had the ecm reprogrammed to check this sensor less so it doesn't wear it out as fast, or prematurely.

[Khein]

Any other clue where to look? We will have this truck again in our workshop and we dont have a clue where to start looking at.

[hercamp]

if fuel system is checked and ok , just need to check air system ,intercooler and coneccions .

maybe the intake manifold gasket , take off air filter to check , check boost press too. that can help to the check list.

[joe5543]

Im having a problem in a client Peterbilt with a CAT C15 engine.
A week ago it came to our workshop for a service and we check injectors, variable valve actuator and engine brake and everithing was ok. The only thing we change because it was not working is the variable valve actuator pressure sensor.
Now the truck has increase in a 50% the fuel consumption and obviously the client is complaining about it.

Anyone has a clue what could be the problem?

Sounds like a bunch of BS, hard to believe the fuel millage goes down by half, tell the guy to take a hike.