fixed the sticky throttle in my 5.3 drive by cable
fixed the sticky throttle in my 5.3 drive by cable I'm posting this because I saw many people had this issue when I was googling for a solution. I have a 5.3 from a 2000 Silverado in my 1979 El Camino. It has a drive-by-cable throttle body. It's always been sticky when trying to press the gas pedal from idle. It seems to stick, and then break free, and of course the car lurches forward, which makes me look like an idiot.
I pulled off the throttle body and completely cleaned and lubed it, which didn't make any difference. With the engine off the butterfly rotates smoothly from the stop, but with the engine running it sticks before coming off the stop. It's like the vacuum holds the butterfly shut, and you have to break it free.
GM has a technical bulletin https://static.nhtsa.gov/odi/tsbs/20...01273-9508.pdf which says to plug the air bypass hole in the butterfly, and screw in the throttle stop so the butterfly is cracked open a bit, which I guess lets the same amount of air bypass. It doesn't give any reason for doing this but if my theory about vacuum holding the butterfly shut is correct, using the throttle stop crew to crack the butterfly open a bit could prevent that.
The TB calls for a special GM rubber plug for the butterfly hole, but it's no longer available, so I used the head of a plastic pop rivet with some plastic JB Weld to keep it in place. I figure if the pop rivet does come loose and go through the engine it won't hurt it too much.
Anyway, the problem is fixed and the car is much more enjoyable to drive now, with no lurching away from stop signs. Hope this helps somebody.
I pulled off the throttle body and completely cleaned and lubed it, which didn't make any difference. With the engine off the butterfly rotates smoothly from the stop, but with the engine running it sticks before coming off the stop. It's like the vacuum holds the butterfly shut, and you have to break it free.
GM has a technical bulletin https://static.nhtsa.gov/odi/tsbs/20...01273-9508.pdf which says to plug the air bypass hole in the butterfly, and screw in the throttle stop so the butterfly is cracked open a bit, which I guess lets the same amount of air bypass. It doesn't give any reason for doing this but if my theory about vacuum holding the butterfly shut is correct, using the throttle stop crew to crack the butterfly open a bit could prevent that.
The TB calls for a special GM rubber plug for the butterfly hole, but it's no longer available, so I used the head of a plastic pop rivet with some plastic JB Weld to keep it in place. I figure if the pop rivet does come loose and go through the engine it won't hurt it too much.
Anyway, the problem is fixed and the car is much more enjoyable to drive now, with no lurching away from stop signs. Hope this helps somebody.
It would happen on a cold engine. I could start the engine, butterfly would stick when I turned it by hand, then turn off the engine and the butterfly would move freely.
When I was googling for a solution, plenty of other people fixed this issue by cleaning their throttle body or by smoothing the TB bore and the butterfly. None of that worked for me; this is the only thing that fixed it.
When I was googling for a solution, plenty of other people fixed this issue by cleaning their throttle body or by smoothing the TB bore and the butterfly. None of that worked for me; this is the only thing that fixed it.