Car surging on cruise control

[FUN2RIDEFAST]

In November I installed a Roush Phase 2 supercharger at Brenspeed and the Dyno run was done with the airbox cover off. They put it back on for my trip home but said it would run better with it off. I took it off the other day and on the highway with cruise engaged the car surged. It wasn't dramatic but it was noticeable. Since the air box cover was the only thing I'd messed with I reinstalled it today. I hit the highway, engaged cruise and the surge is gone. Any explanation for this. All I could come up with was increased airflow and the ECU in a learning process for fuel management. process.

Sponsored

 

[Mr. Met]

Not sure how that would affect the cruise control, but why would it be better to run it with the cover off? That would just let more hot air from the engine bay into the intake.

 

[AMC401V8]

Put a new throttle position sensor on it. Hope this helps.

 

[FUN2RIDEFAST]

Not sure how that would affect the cruise control, but why would it be better to run it with the cover off? That would just let more hot air from the engine bay into the intake.

I'm not sure either but after putting the cover back on the surge in gone.

 

[Ruiner46]

The change in airflow is probably tricking the MAF sensor. With the car on the dyno, they didn't have highway speed levels of airflow into the grill. With no cover, the air flows differently into the airbox and through the MAF. Generally increased or decreased airflow is handled just fine by the tune, but if the air is flowing through the MAF pipe differently, then it may not be measuring the airflow accurately anymore. Removing the cover may make more air bypass the sensor itself by changing the amount of flow on the sides of the pipe (sensor is in the center). If the tuner is using a standard Roush calibration for the MAF, then it is intended to have the box closed, and the values in the tune representing airflow were created with a closed box.

 

[FUN2RIDEFAST]

The change in airflow is probably tricking the MAF sensor. With the car on the dyno, they didn't have highway speed levels of airflow into the grill. With no cover, the air flows differently into the airbox and through the MAF. Generally increased or decreased airflow is handled just fine by the tune, but if the air is flowing through the MAF pipe differently, then it may not be measuring the airflow accurately anymore. Removing the cover may make more air bypass the sensor itself by changing the amount of flow on the sides of the pipe (sensor is in the center). If the tuner is using a standard Roush calibration for the MAF, then it is intended to have the box closed, and the values in the tune representing airflow were created with a closed box.

Thanks. That's pretty much what I was thinking. It immediately stopped doing it when I put the cover back on.

Sponsored