70mm BBK TB mechanical stop adjustment

edspringer

Registered User
:confused: I cannot find my install instructions for my 70mm TB. I'm having a rough idle problem with my 94 and I want to verify the mecahnical stop adjustment. I thought the initial engine off adjustment was to back off the TB screw and then tighten down until there is .020" gap between the screw and the stop. Then turn the screw 1 full turn clockwise. Then, if necessary, adjust the RPM with the air screw. Is this right?

Ed Springer

90 Black XR7 5-speed: 70mm TB, Fresh Air Intake, '94 Supercharger, 5% SC Pulley, Raised SC Top, I/C Fan, Under-drive Pulleys, 190 l/h Fuel Pump, 36# Injectors, Headers, Magnaflow Muffler (no cats) with stock resonators, 3:27 Gears, Ripper Shifter, 73mm CL MAF (Blue Tube), Magnacore Wires, NGK Iridium Plugs, Royal Purple Lubricants and Rear Spring Air Bags.

94 Red SC Auto: 70mm TB, Fresh Air Intake, Stock 90 SC Pulley, Raised SC Top, I/C Fan, Under-drive Pulleys, 190 l/h Fuel Pump, 38# Injectors, Headers, Raven Muffler (no cats) with stock resonators, 3:73 Gears, 76mm CL MAF (Gold Tube), Magnacore Wires, NGK Iridium Plugs, Royal Purple Lubricants, TRANSGO Shift Kit, Pro-Torque 2500 Stall TC, Haydon Auxiliary Transmission Cooler, Tokico Struts & Shocks, American Racing 17” Sniper Wheels, Michelin Pilot Sport A/S Tires and 235 RWHP with 315 LB-FT Torque.
 
Well you don't want the throttle butterfly to bind in the closed position nor do you want the butterfly open so far that the IAC can't lower the idle. I set mine by feel. Just make sure to check your TPS voltage after you are done. You don't want more than about .95 volts.

Jerry
 
From your cars listed you seem to know what your doing around SC’s. But have you checked for a vacuum leak? Had a rough idle on my 89 and found a small hose leak and cured it right up. Sometimes it the simple things.
 
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