Didn't notice until I looked closely at Daustin's picture of his turbomaster setup that there could be something wrong with my turbo. My wastegate arm swings 90 degrees from the purple position (9 o'clock) to the red position (6 o'clock). Stops dead there at the bottom, but I see that possibly it should be moving further? What impact would that have on drivability? My actuator is shot, reason I was looking at fabbing up a turbomaster. I have it in the 9 o'clock position now and it ran good, when in the 6 o'clock position it stumbled whenever I stepped on the gas.

It's been operating in "backup fuel" mode for the past year that I've owned it until I replaced the injection pump last week. Fix one issue, another pops up!

I've got a 94 with the GM-4 turbo. Sure appreciate the input.

I think that is a pic of a GM 8? Anyway I have a GM4 on my 95. IIRC pulled all the way to front of truck is closed. It does not need to open a full 90 degrees. In fact the Heath Turbo master will not let it. I would say roughly from closed pos mine moves maybe 30 degrees ? It doesn't need to open much. Heaths TM has a bolt on bracket on the wastegate arm that changes the geometry of it for more consistent setting. Sort of being able to set it and forget it.

Yes, pulled to the front of the truck is closed on a GM-4.

GM4 The angle of the lever is different from the GM8

Doesn't the GM-8 WG close in the 'up' position?

I think he has a GM4 but was trying to explain his problem with a pic of a GM8

If his truck is stock, then it is the same as mine, which has a GM-4.

The picture shows a GM8. I think the outline drawn is similar to the GM4 if that helps anybody.

Should have clarified. I have a GM4 turbo. It swings from the back (arm pointed towards the cab) to straight down and stops. When I ran the truck with it in the down position, I was blowing a lot of black smoke and the truck really faltered under hard acceleration. Ran a ton better with it apparently in the fully closed position (arm pointed towards cab). Does that jive? It would run better with no boost versus partial?

Hmm....is it the stock waste gate controller? On my GM-4, the actuator is towards the front of the engine compartment. When it has vacuum, the arm is pulled closed, which means that the arm movement is horizontal towards the front of the truck. When it is open, the arm moves back towards the cab of the truck.

That pic i posted is a GM-8 (Rigger's turbo i think from the green), with your's being a '94 the actuator is different like they are saying above. When the earlier models relieve pressure the arm moves from the 6'oclock position toward the 9'oclock position. (like a gm-3 or 4) Look on the trubo and let us know exactly what turbo you have, i have pics of a turbo master i made for a GM-3 as well if you want those. (i've made several of these critters lol) :D
Don

my 93 just stays about 7-8 oclock position for the last couple years

Here are a couple of pics of the turbo master i made for the GM-3. Hope that helps.

Don

Daustin - great pictures, thanks! Do you have any parts list and build tips? The can on my wastegaste is already pre-bent, so using lower housing would be easy. Appreciate the help!