Explain to me what controls boost...

[steved]

Ok, I'm thinking I've got a nuisance boost control issue... what mechanical components (not including the ECM) control the boost pressures? I'm thinking that either the wastegate is getting a faulty signal or the wastegate controller is getting weak.

 

[Wingate]

things that can control/affect boost... . inlet air restriction, exhaust restriction, lack of fuel being injected, (dead hole. etc... ) injection timing...

I'm curious as to what yours is doing?. . A friend of mine has an 04. 5 that he's been complaining about lately. He says that when he rolls into it, if he has to lift for a split second and get back in it, he has to wait forever for the turbo to light back up... . Almost like the wastegate gets confused so it just stays wide open for several seconds. His truck is stock with approx. 120K on it. He drives kinda aggressive, but I'm really trying to get him to buy a Smarty. I think it would help his situation.

 

[steved]

I have an occasional "warble" in the boost tone... almost like whatever controls boost can't overcome the pressure or whatever controls the boost control can't make up its mind what boost it wants to see?



Pressure is steady as far as I can tell on a digital gauge... and its so random, started doing it a few miles from and did its thing for a couple hundred miles and hasn't made a peep since... 1200 miles later. It does it all the time one trip and not at all the next.



Mine started right after injectors were finally fixed, about 160k... still does it at 215k. The turbo appear to be tight with almost zero play. With the Jr, I can see 40psi without issue.

 

[cerberusiam]

Boost is controlled by the ECU by sending a PWM signal to the WG controller that allows boost pressure into the WG actuator. The WG controller is really a crude electro-mechanical device that suffers all kinds of issues and failures. If there was a constant culprit that would probably be it. The actuator could be getting sticky also.



If your boost numbers aren't bouncing and it doesn't exhibit the noise you hear all the time, possibly just air density and your air intake system are combining to create an audible harmonic?