sticky bigblock tbi

[bigblockdually]

hey guys i was wondering if you could help me out with my tbi on my 87 7.4L. Alright heres the problem the flaps in the tbi rub against the walls of the throttle body. when the engine is cold the gas pedal is nice and easy to push down just like it should be. but when it heats up the flaps start sticking and you cant just ease into it around corners or from a stop you have to mash it for the pedal to even move but once it goes down about an inch it moves freely its just frustrating trying to drive it because you have to fight with the pedal the whole time. its not the cable because i disconnected it from the tbi and it moved in and out as free as anything but when i opened the flaps by hand with the engiune of you can see and hear them scraping until they move to a certain point then works fine so i was wondering if maybe they make a bushing kit or if there is another way to resolve this or do i have to buy another tbi unit thanks

[STOCKISH]

You could buy a used tbi for the price of getting the throttle shaft bushings replaced. When I worked at the GM dealer we used to use emery cloth to smooth the area aroung where the throttle blades would touch the inner wall of the tbi housing. Seemed to be a fairly common issue. Also, make sure the screws that hold the blades onto the throttle shaft arent loose. DONT try to take them out though, they WILL MOST LIKELY BREAK.

[N2TRUX]

Is it carbon build up? I have seen that problem before being caused by carbon. I cleaned the inlet with carb cleaner and it solved the issue.

[bigblockdually]

thanks guys i lightly sanded the walls with 2000 grit and it solved the problem hopefully the shavings dont destroy my engine

[STOCKISH]

I would have stuck a rag in there first but thats just me. Besides, I dont imagine anything that came off using 2000 grit could cause an issue.