I have a 06 boss 5.4

It came with the roushcharger.

It seems to always stay in boost bypass. So far I can say that the acuator works if you pull the vac line off of the solenoid. If you unplug the signal line for the solenoid the acuator will close. It seems like the ecu is not switching the solenoid. I have checked all connections and vac lines. Everything looks correct.

Does anyone have any ideas?


Thanks.

 

With a Roushcharger your bypass valve is electric and runs off a signal from Intake Manifold Runner Control. On a stock intake there are throttle secondary's that are actuated at around 3400 rpms. The plug for this is at the back of the motor and it carries the signal which is now used to open and close your bypass valve. It's a great idea from Roush and makes tuning them with the drive by wire much easier than dealing with the vacuum bypass. Unfortunately Roush is the only company utilizing this method on the blower kits for these trucks. The downfall of this setup is that the tuning that comes with a Roush blower doesn't command the bypass valve open till somewhere in the mid 3000rpm range thus delaying boost till your running her pretty hard. However this is easily changed with custom programming which is nice as you can dictate exactly when and where you want boost.

So are you not seeing boost at all?

 

Sounds like he might be saying it's never going into boost. It could be they wired up the solenoid incorrectly. Since it's behind the manifold, it would be a job to check out. But since the solenoid runs off an electric signal, it could also be at fault.

 

Yeah I'm not sure what he's getting at. The trucks an 06. Surely it hasn't been this way since day one? Perhaps the truck is new to him and has this issue? It so hard to see through the internet. I'll never buy internet glasses from Big Lots again lmao. Hopefully he'll shoot us a few more details.

 

I havnt had the truck but a few months. I installed a boost gauge and found out that it was not boosting up. It will boost up at WOT if I drive it with either the boost bypass acuator vac tube disconected or if I unplug the signal wire to the bypass solenoid.

I have checked all the vacuum lines and wires according to Roush installation instructions. I have not found anything wrong.

 

It does seem to stay in boost by pass at all times. The way the solenoid is set up, leads me to think that the ecu should be cutting off voltage to the solenoid, so that it closes the acuator. If I unplug the solenoid the bypass plate closes.

 

Dumb question but does the truck feel powerful? Does the blower whine? Just wondering if perhaps the boost gauge is incorrect or hooked up wrong. Though it is possible to have a faulty bypass or actuator.

 

That was the first thing I checked. I tried two different gauges and they read the same. The charger does whine but power feels the same as a stock f150. I get 8-9lbs of boost on the gauge if I unplug the solenoid and drive it at WOT.

I have had a few conversations with Roush Tech line, but they have not been much help. They think possible bad solenoid. If the solenoid was bad then it wouldnt open or close when you unplug it, imo. Not sure because they cant tell me how it works. They said I should see 12volts at the solenoid at idle, which I do. The 12 volts at the solenoid is what opens the valve so the acuator goes into bypass mode. If this is so, should it take away the 12 volts at WOT to close the bypass?

 

I would think open is the default position. Since open prevents boost then it should open when theres a failure within the accuator or solenoid so your not making boost non stop. At least in a perfect world it should work that way. Personally I would start by replacing the solenoid. Can you move the acuator by hand to insure it's not binding?

 

The supercharger works off a couple of wires from the IMRC. I once turned off the IMRC in my tune and the boost bypass stayed open all the time. Here is a link to Roush's install instructions so you can determine if the solenoid vacuum is plumbed correctly. There is a part number for the solenoid, which appears to be a Ford part number.

 

I can move the actuator by hand. With the truck off the actuator lever drops down and closes the bypass plate on the supercharger. When you start the truck the solenoid turns on and allows vacuum to operate the actuator, which then opens the bypass plate.

 

So then it is operating as it should at idle. Curious that your having the issues at speed.

 

Im starting to wonder if someone might have installed a hand help tune and turned of the motion plates.

I guess my next step is to have a Ford tech check the ecm operation.

 

I wouldn't even waste the time. Call Mike Troyer and have him send you custom tunes and a handheld and you will be grinning from ear to ear after the first drive.

 

My suggestion would be to hook the vacuum line directly to the boost bypass actuator motor in the meantime. In other words, completely bypass the solenoid.

I wouldn't bother having the ECM checked out because the dealer is likely to reflash the PCM and you will lose the Roush calibration as each PCM had to be sent to them for the proper calibration. Your truck will not run on an OEM calibration.

It's not likely someone turned off the IMRC in the tune. That would be a stupid thing to do. I did it because I have the SCT software and wanted to see what would happen. It would not be a user adjusted parameter from the programmer (i.e. reflash tool).