WG funiction question

[SeattleSy#1255]

how can i tell is something happened to my WG (stock setup)....reason i ask is i had normal boost then i got a small backfire and wammo, i'm only getting base boost now.........all vacuum hoses are checked and rechecked, tried two working boost selenoids, and tried differnet settings on ultimate........i read on a previous post to use a pressure tool used for radiators to test it, but that is pretty impraticle as i don' thave those tools...how can i tell is the WG is toast, or perhaps other suggestions?

 

[SeattleSy#1255]

geeeeeeeeez, knowone can tell me how to tell if the WG is functioning cofrrectly?

 

[dgoodhue]

To test my wastegate actuator operation, I used a mitivac, some vaccum line, vacuum T, and stand alone boost vacuum guage. You could probably just get away with a mitivac, it should take about 3 pumps with the hose on the outlet of the mitivac (ie boost, but the mitivac doesn't read boost only vacuum) At this point the actuatator should just barely move and the 4th and 5th pumps it should fully extend.

I would make sure the wastegate rod is properly adjusted, I have seen the rod too long so that it is always bleeding off boost (and slow to build boost) If you have an ultimate chip and havent' adjust your wastegate tighter from the factory setting, it will take or 4 secs or so to hit full boost.

If these still don't work it is either your factory boost solenoid or ECM/wiring issues.

 

[SeattleSy#1255]

thanks dave...

however the truck was fine at its settings for months and just suddenly backfired one time and now i'm stuck with base boost.....no vacuum lines exploded or poped off anywhere...i can't find a damn thing wrong at all...wg i have adjusted at 100 different settings and i have tried two boost solennoid which i know are good and work....

what about the cat busting inside somehow would that do anything like this?

 

[MikeRenz]

what about the cat busting inside somehow would that do anything like this?

that would most likely cuase overboost, not "underboost".

The only time my ty has backfired is when any of my turbo to intercooler line popped off, or if the intercooler popped off the throttle body. Check all of these connections and make sure that all those are air tight.

Also, just becuase you're vacuum lines are still connected, does mean they could have cracked or gotten a pin hole in them.

Its also possible that you're wg solenoid went bad. They become pretty brittle over time. I've broken the nipples off of it before. Pretty cheap fix, its ony $16 pr $18 straight from gm.