High Idle Problem with 58mm BKK... SOLVED
#16
There were a lot of issues with the aftermarket throttlebodies over the years. Some were sticky due to the blades or wouldn't close all the way because of the punched out pieces used to make the linkages, like the BBK/Elelbrock discussed here. Others had weak return springs and need a second spring to shut the blades. In some cases, the plastic cover rubs the cable and causes a high idle. Some throttle bodies did not have the IAC holes in the same configuration causing idle problems, and there is a mod to get that right. Also, some throttle bodies put the TPS switch in the wrong position, so it needed to be slotted to get the right voltage. And if you put a 58mm on an A4 car, you had better know how to reprogram the transmission tables in the PCM or nothing is going to happen at the right time in relation to engine load. There were LOTS of issues with these parts.
#17
There were a lot of issues with the aftermarket throttlebodies over the years. Some were sticky due to the blades or wouldn't close all the way because of the punched out pieces used to make the linkages, like the BBK/Elelbrock discussed here. Others had weak return springs and need a second spring to shut the blades. In some cases, the plastic cover rubs the cable and causes a high idle. Some throttle bodies did not have the IAC holes in the same configuration causing idle problems, and there is a mod to get that right. Also, some throttle bodies put the TPS switch in the wrong position, so it needed to be slotted to get the right voltage. And if you put a 58mm on an A4 car, you had better know how to reprogram the transmission tables in the PCM or nothing is going to happen at the right time in relation to engine load. There were LOTS of issues with these parts.
#19
Tb
my buddy has a holly 58mm on his car that has the same symtoms do you guys think it could be the same deal? I know when we first put his on we had to adjust the position of the blades because they had a catch in them at closed throttle.
#20
I used a thickness of a piece of paper to set the blade opening, then added an extra spring to make sure it closed against the stop every time. Then you can log the car as you're driving around and see where the IAC counts end up at idle and set that as the Park IAC parameter so it doesn't have to hunt to fiind where it needs to be every time for idle air when you let off the gas and come to a stop.
As far as the Holley, I thought I remembered Fred Forsyth saying they had weak throttle springs, but I could be mistaken. Doesn't hurt to add an extra spring in any case as long as it's not too stiff. The beauty of an extra spring (assuming you only have one in the first place) is that it can save your butt if the first one fails. So, it's a good racer mod in any case.
As far as the Holley, I thought I remembered Fred Forsyth saying they had weak throttle springs, but I could be mistaken. Doesn't hurt to add an extra spring in any case as long as it's not too stiff. The beauty of an extra spring (assuming you only have one in the first place) is that it can save your butt if the first one fails. So, it's a good racer mod in any case.
#23
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