No wastegate?

[WHendrix]

Hey guys, I just bought a '93 (extended cab LE 3. 54 w/Getrag), which is very low on power. I had a brand new one in '93 which I dearly loved, and as I remember it would pull a small house without breaking a sweat. This unit (at 155k) wouldn't pull your hand out of your pocket, although it did get 22mpg (unloaded) from Pennsylvania back to Georgia. Also, I remember my old one had a distinct turbo whine at peak, while this one is almost completely silent (the turbo, not the rest of the truck!).

I suspected a plugged filter (it was fine), an induction leak (none found) or a stuck-open waste gate, except apparantly there is no waste gate!

My question is, how is turbo boost regulated in these trucks? I see a small hose that runs from the head to what appears to be a diaphram housing on top of the injection pump, is that how it's done? I have yet to install a boost gauge and pyrometer, but that's next. Suggestions?

 

[Bob4x4]

You don't have a wastegated turbo. The turbine housing is so big it will not build excessive boost. You would see a performance gain by replacing the turbine housing with a more appropriate 16cm housing

 

[cerberusiam]

No WG on the 93's. The housing is big enough and the fuel limited enough they won't over boost.



The boost will be controlled by the amount of fuel you throw at it. The line from the head to the IP is the boost rference line for the aneroid to control low\no boost smoke. Now if it has a leak or pin hole it will feel like a dog because boost never builds in there to increase fueling.



Start with the aneroid, star wheel adjustment, and fuel pin adjustment and see if that makes a difference.

 

[glhs]

On a 93 you would have a 18. 5 cm turbine housing which should make 14-16 lbs of boost.

If it were a 92 it will have a 21 cm housing which will make 13-15 lbs.

A 16 housing will add 1. 5-2 lbs over the 18. 5 and about 3 lbs over the 21 housing.

I prefered to run the 14 housing for best overall performance.



Check that little air line from the head to the afc (air fuel control). If it has a leak, you will be down on power for sure.