I turned the fuel in 1 turn and my smoke screw out 1/2 turn. Does this sound right? I can notice a difference in power. I am still getting some black smoke when accelerating through the gears until the turbo spools up, then it stops. None at cruise speed. I turned the smoke screw out further, but felt a drop in below turbo spool up acceleration, so I went back to a 1/2 turn out. Should I mess with anything else? Also, what is the idle RPM supposed to be for a 92 manual 4X4?

 

I'm assuming you have a pyrometer? If so, take the AFC cover (that's the part the smoke screw is in) off and pull out the diaphragm and fuel pin. You'll notice that the fuel pin is eccentric. Put the pin back in so that the deepest part of the taper is toward the front of the truck. This maximizes your fuel when the turbo is making boost. Before you put the pin and diaphragm back, though, pull the spring out and use a screwdriver to turn the star wheel (thing that looks like a gear) a couple turns clockwise. This makes the fuel pin move more easily so you get the extra fuel with less boost. Keep tweaking the star wheel and smoke screw until the truck responds the way you want without smoking too bad (very subjective, I know). The softer the star wheel is set, the farther out you can back the smoke screw and still have good response. Idle should be 750 RPM with the A/C on.

 

No, I don't have pyrometer. I don't plan towing much with this truck. I just wanted a little more zing. Do you think I could hurt anything without a pyrometer? I am not really concerned with more full fuel power. I wanted a bit more power shifting through the gears at normal driving. I have 255/85r16 tires with the 3.54 gears in the back. I think the slightly higher ratio hurt my accleration and am trying to regain it. Any other suggestions?

 

Yes, you can easily hurt the truck by turning up the main fuel screw and not having a pyrometer. You don't have to be towing to get it hot. Don't let it bog down until you get a pyro gauge on it, as long as you keep it wound up it'll probably stay cool enough. My only other suggestion it so get a pyrometer.