[Porsche944]

OK, since going back to the stock throttle cam made things worse, I'd wager we're looking at adjusting the TPS, throttle mechanical stop, and the throttle cable.

To start with, get yourself some carb cleaner, paper towels, a 13mm wrench, a 10mm wrench, an 8mm wrench, a 6mm Allen Wrench, flat and phillips screw drivers, and a pencil and paper.

Remove the throttle body(Don't loose the red O-ring). Use a flat blade screw driver to bottom out the idle by-pass screw. Count the number of turns (fractions are OK), and write that number down.

Remove the idle by-pass screw. Inspect the O-ring. Clean the screw and O-Ring (if it's in good shape).

Loosen both screws on the TPS. Use the 8mm wrench to loosen the jam nut on the throttle plate mechanical stop screw. Back the stop screw out until it does not touch the throttle stop arm. Clean the throttle body bore, throttle plate, idle by-pass port, and both vacuum ports. NOTE: If either vacuum port is plugged, use a small sewing needle to open the port. Make sure both ports are open.

Once the throttle body is clean, adjust the mechanical stop until it just touches the throttle plate stop arm, and then turn the screw an additional 1/2 turn. Tighten the lock nut.

Hold the throttle plate closed and adjust the TPS so the TPS makes a soft 'click' just as the throttle plate comes off of the seat.

Install the idle by-pass screw and set it for the appropriate number of turns open.

Install the throttle body.

To adjust the throttle cable, loosen the jam nut where the cable goes into the fire wall, and then install the cable onto the throttle cam. Using the adjuster, set the cable so that there is not too much slack, but enough to let the throttle plate close fully. Listen for the TPS to click each time the throttle closes. Once you have this set, tighten the jam nut.

Connect a tach to the coil primary wire (green), start the engine, and use the idle screw to set the idle to 950 +- 50 RPM.

Disconnect the tach and go for a ride....

BTW: I'd use the round throttle cam. The stock cam sucks.