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Cleaned Throttle Body For The First Time

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Old 12-25-03, 09:27 AM
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gserep1
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Default Cleaned Throttle Body For The First Time

Well I finally decided to clean the throttle body assembly of my GS last night. Armed with a big can of Berryman's Carb Cleaner and a 10 mm socket, ratchet and extension (the only tools you'll need), I started taking apart the induction system.

The 10 mm socket takes apart the entire upper end. The air cleaner assembly comes off, along with the hoses on the mass air system and the resonator.

The throttle body butterfly plate is directly up front with the plumbing removed. It is heavily spring loaded to the closed position by an electro mechanical motor. It is a very complex piece that controls idle and also rate of acceleration when the car is in the "snow" position. To prove this, I moved the accelerator cable linkage, and noticed that the butterfly plate did not move at all. The cable assembly is on the passenger side of the throttle body, and the motor is on the driver's side of the throttle body.

NOTE: This may also explain why there is a lag between the time the accelerator is pushed, and the time it responds. This motor has to activate and move the butterfly plate in the position in direct proportion to the distance the accelerator is pushed. The TPS is responsible for sending a signal to the computer, and the computer activates the motor.

The butterfly plate was heavily coated with black carbon on the outside of the throttle bore. It was evident before opening the plate. Pushing the top of the plate with a finger exposes the bottom of the bore. It was FILTHY. I initially decided to just spray some cleaner on a rag and WIPE the bore out, but when I saw how bad it was inside, I used the whole can inside the intake manifold. I sprayed heavily at the top because there there are vacuum hoses and ports directly on top of the throttle body. These ports were COVERED with carbon. I also removed each vacuum line and blew car cleaner through the port and watched the fluid come out into the bore.

Spray liberally around the inside the bore, and work the butterfly bore back and forth to make sure it is not binding. This motor also controls the cruise control, so it is vital to the proper idle. When the air conditioning is on, the motor positions the plate for the correct idle speed.

Assemble the unit, and start the car. WARNING... if you have sprayed a lot of cleaner in the bore, be prepared to spin the starter a few times before it catches. do not give it any throttle. The engine will shake a lot, and the dirt will come out of the tail pipe. There will be a lot of smoke. Let it settle down. The idle will be fast (1500 to 2000 rpm) for a few minutes until the computer resets everything. The idle will be smooth afterwards.

Drive the car and enjoy!
GSEREP1
Old 12-26-03, 08:18 PM
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O. L. T.
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Thank you for the writeup, send this link to Rich at intellexual and you may get into the faq.
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