Help! - Throttle Body Linkage Problem
Thread Starter
Burning Brakes
Joined: Mar 2001
Posts: 1,228
Likes: 17
From: Mansfield Texas
Help! - Throttle Body Linkage Problem
I recently installed the BBK 52 MM TB and I have a major problem I need help with. I have a problem that is pissing me off. When I get off the throttle, the accelerator linkage is not returning all the way back to the idle position and therefore causing the RPM's to hang up at 1300 opposed to the desirable 700 RPM idle speed. I attempted to remedy this by attaching a return spring to the linkage but this caused my accelerator pedal to be too stiff and **** me off again! Is this a common occurance for BBK or can I correct this on my own? Thanks in advance.
Team Owner
Joined: Aug 2000
Posts: 42,935
Likes: 20
From: Sydney, Australia
CI 6-7-8-9-10 Veteran
St. Jude Donor '07-'08-'09-'10-'11-'12-'13-'14-'15-'16-‘17, '22
Re: Help! - Throttle Body Linkage Problem (wheeljo2)
With the motor off check if the butterflies inside the throttle body to see if they are binding on the wall of the throttle body before they can return to the fully closed position.
If this isn't the problem, check your IAC valve. It may not be set correctly or may need replacing. If you don't have access to some sort of scanner to monitor IAC counts, I'd pull the IAC valve and see if it moves slowly by hand (this is okay) - but be careful and don't be too forceful. If its stuck, buy a new one. If not, set its position so that the measurement from the metal tip to the top of the rubber washer between it and the TB is 28mm and reinstall it to see if the problem is still there.
If the butterflies are binding on the edge of the TB, I would firstly see if I could fix it by loosening the butterflies and adjusting were they sit on the shaft so that they no longer bind. Alternatively, you may need to file/sand back the edges of the butterflies so they no longer bind. I had my 48mm TB modded locally and had to go through the whole IAC replacement/adjustment and throttle butterfly adjustment (butterflies were not machined well) process to get my idle reasonable.
NOTE: do not file/sand the butterflies unless you are sure that is the problem!
HTH
If this isn't the problem, check your IAC valve. It may not be set correctly or may need replacing. If you don't have access to some sort of scanner to monitor IAC counts, I'd pull the IAC valve and see if it moves slowly by hand (this is okay) - but be careful and don't be too forceful. If its stuck, buy a new one. If not, set its position so that the measurement from the metal tip to the top of the rubber washer between it and the TB is 28mm and reinstall it to see if the problem is still there.
If the butterflies are binding on the edge of the TB, I would firstly see if I could fix it by loosening the butterflies and adjusting were they sit on the shaft so that they no longer bind. Alternatively, you may need to file/sand back the edges of the butterflies so they no longer bind. I had my 48mm TB modded locally and had to go through the whole IAC replacement/adjustment and throttle butterfly adjustment (butterflies were not machined well) process to get my idle reasonable.
NOTE: do not file/sand the butterflies unless you are sure that is the problem!
HTH
Le Mans Master
Joined: Feb 1999
Posts: 7,254
Likes: 0
From: Custer SD
Re: Help! - Throttle Body Linkage Problem (wheeljo2)
Disconnect the throttle control cable and the cruise control cables and blip the throttle. If it still hangs up, return it to whomever you bought it as defective. If it doesn't hang up, try blipping it with just the throttle control cable and then just the cruise control cable and see if either causes it to hang up and take care of the offender with due prejudice.
