its a 97 chevy 3/4 tonne with auto transmission. When accelerating...you can hear the turbo kick in at around 2000 rpm...but as fast as it kicks in it stops and then cycles like this until power is no longer needed. You can feel the truck speed up and down as the turbo kicks in and out. Is this a wastegate problem or is this the way the turbo works ( my first 6.5 turbo...so new to me). Other than that it runs fine....just curious if it is fixable.

see if the actuator arm is sticking, if not then it might be your waistgate solenoid

Probably is the wastegate solenoid. That is how my truck acted when the solenoid was gone.

I believe these are designed to operate just like you described,boost is in and out

The factory ecm programing is set up that way for some goofy reason. A reflashed or reprogramed ecm eliminates the cycling. The factory programing will cycle the turbo boost off when you need it most.

Thanks guys....that is exactly what it does....feels like it is cycling, but when you call for power the boost cuts in strong again ....but then starts cycling again. It is very annoying going down the highway....i can hear my turbo very well....up....down...up...down. How do you reprogram the ecm...or can you get an aftermarket unit.
The truck doesnt smoke at all...has lots of power....but the dang thing just wants to drive me crazy with the turbo cycling.

Check for leaks on the tubes then change the solenoid.

Better yet, get TurboMaster.

[QUOTE]Check for leaks on the tubes then change the solenoid.

Better yet, get TurboMaster.[QUOTE]



If you put TM on 97 won't service light stay on all the time

Not if it has the F engine code in the VIN.

Although, doesnt the factory ecm boost up to 8 psi or so then runs back down to 5 or so at cruising speed? thats what i thought anyways. If it goes up then down to nothing then up and to nothing again i would say its either a vacuum leak or your waste gate solenoid. Mine would was doing something like that as well, but it would boost then nothing but then it would stay at 0 for a long time. I changed my solenoid and then it worked awesome. Only like 40 bucks from the shop anyways. Hope that helps. Also on the turbo master comment, if your gonna get a turbo master, you should get a reflash anyways to get away from over boosting the factory one. Otherwise you wont really gain much since itll hit a certain boost then shut the fuel off... i think anyways

so if i have F engine i can do TM on it and not light come on.I thought that you have have puter reflash

it should work, still would recommend getting a reflash though.

Had the same here..in and out..........

Today i put a new solenoid in and the problem is gone !!:)

yes was just the solenoid.....changed that in a few minutes,now i have power to spare lol. My 07 6.0 litre gasser cant spin the tires in second...but this old diesel can lol...and my average mpg is 19-21....should have got one of these 6 years ago thanks again guys