Fast idle -- one more thing to check

[Eagle]

Having just seen a question about fast idle, two days ago Old Faithful started acting up. The throttle would stick, and if I took my foot of the gas and disengaged the clutch, the idle would be around 1200 RPM. Then if I tapped the pedal sharply, the idle would drop to normal.

 

That lasted about a day. Then the idle went to 2500 RPM and tapping the throttle didn't bring it back down. So after work this evening I attacked the throttle bellcrank lever with PB Blaster. To no avail. No improvement, and things felt VERY sticky. Tried to remove the air horn to check the throttle body. Naturally, one of the three screws won't come out. So I went back to trying to lube the linkage. Extended the cable as far as possible and sprayed with white litium grease. No improvement.

 

Finally I popped the little plastic ball socket off the throttle body end of that part of the linkage. That confirmed that the throttle body was free, the drag was between there and the pedal. Kept moving the rod up and down, hoping all that PB Blaster would soak in. Accidently popped the lower socket off the ball on the lower bellcrank arm. Okay, tried moving it by hand, without the rod. HEY! It moved freely!

 

So I sprayed a bit of white lithium grease into each of the plastic cups on the ends of the linkage arm, snapped the arm back in place -- and it's working perfectly. I guess after 20 years, plastic loses any self-lubricating properties it might once have had.

[HOrnbrod]

Yeah, I've been lubing the various linkage and cable ball and socket joints w. the white lithium grease for years; throttle body, tranny, and even the load sensing valve out back pretty regularly for years. Mainly because of sticking problems caused in the past w. carb linkages. But have not ever tried to lube a shielded cable's internals, except on a motorcycle or bicycle. Maybe I should do that occasionally too.......... :roll:

[james750]

Yes, plastic will eventually lose its "self Lubricating" properties. If exposed to UV or high heat scenarios (high heat only applies to thermosetting plastic), the plastimers in the plastic will be drawn out of it therefore leaving it brittle, dry and it will crack and break easily.