Sticky pedal

[Scappoose]

My throttle is sticking, bad. It’s not electronic, it’s mechanical. When I press the pedal, there’s a lot of resistance, then pop, it opens. I checked the linkage, lubed the cable and lever on the throttle body and it still does it. Here’s what’s weird, when it’s cold, it operates freely, then as the car warms up, it gets worse. Then, usually, it will get better and free up. If I drive it longer, it gets sticky again.

Now two months ago, I had the upper intake, EGR spacer and throttle body off. They were gunked up, so I cleaned out the spacer, the IAB and the throttle body. My 91 has the decal that says "don’t use solvents or cleaners" on the TB. I didn’t. I used a rag (and believe me, this took a while). I remember reading somewhere that the butterfly was ceramic coated to reduce sticking. Can the ceramic wear off? Had someone possibly used cleaner and when I cleaned it off I removed the natural lubricating properties of the gooey buildup?

It would make sense that as the motor heated up, the metal expands enough to stick, then when the thermostat opens, it cools it off enough to free up the mechanism until it heats up again and sticks. Does this sound familiar to anyone? Am I SOL, or is this an excuse to buy a new, larger throttle body.

Thanks.