Pietenpol

Will try to lay out as much info as I can. '90 cali Vert with non-cali ecu

When I start the car in the morning, it starts easily enough. On the initial rev (not touching pedal) the car will drop to almost stalling. I tap the gas briefly and it settles into a surging idle from about 750-1000 rythmically. If I hold the idle up say around 1500 it will surge exactly the same amount there. When driving the check engine light is on. It goes out with the slightest pressure on the gas pedal. I was poking around today under the hood and the cable at the throttle that goes toward the passenger side seemed extremely loose. I tightened it up a little. I noticed that at a certain tightness, the check light would go out. At that same point, the surging would stop but the idle was rough. Another thing I found that would stop the surge without making the idle bad was a part towards the front of the throttle body. 2 units almost identical. Black plungers riding on a cam. If I pushed in slightly on the closest one to the front, it seemed to eliminate the surge and still idle fine. Not sure if it had any effect on the check light.
Usually after warming up and driving a little, the surge disappears.


Any thoughts...