1990 V8Q throttle stuck open (redux)
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1990 V8Q throttle stuck open (redux)
Back story, the throttle was known to be hard to return to 0%, but it always did. On a drive I floored it and it stuck open and wouldn't return. The car's been parked all winter and I'm now getting to it.
I'm at it again with the throttle. While I was taking the throttle body cover of I saw the butterfly valves were about 60% open. Curious, I thought, I moved them back in place. It was a little difficult to move them back, but they went back to 0%. OK, so the rod needs lubed. I took the tottle body off and verified that the spring in the throttle body was OK, it was, everything moves from 0-100% with no issues. I started to play with the rod a bit and it seems to move just fine, except it gets a little stiff, supporting that I needed to lube it. However I could not find out where to lube it at.
I went back to where the throttle cable attaches at the rear of the engine and verified it worked, it does. I noticed that when I move it that there is no spring tension on that spring, or it doesn't feel like it is. I moved it with my finger and it was loose (remember, the throttle body is removed). Is this spring shot or even relevant?
What are your thoughts? Attached are a pic of what the spring looks like to compare to yours and a short video of me physically manipulating it to show how free moving it is.
https://www.dropbox.com/s/4bleutludp...34.31.jpg?dl=0
https://www.dropbox.com/s/2cbggq4ppp...35.02.mp4?dl=0
I'm at it again with the throttle. While I was taking the throttle body cover of I saw the butterfly valves were about 60% open. Curious, I thought, I moved them back in place. It was a little difficult to move them back, but they went back to 0%. OK, so the rod needs lubed. I took the tottle body off and verified that the spring in the throttle body was OK, it was, everything moves from 0-100% with no issues. I started to play with the rod a bit and it seems to move just fine, except it gets a little stiff, supporting that I needed to lube it. However I could not find out where to lube it at.
I went back to where the throttle cable attaches at the rear of the engine and verified it worked, it does. I noticed that when I move it that there is no spring tension on that spring, or it doesn't feel like it is. I moved it with my finger and it was loose (remember, the throttle body is removed). Is this spring shot or even relevant?
What are your thoughts? Attached are a pic of what the spring looks like to compare to yours and a short video of me physically manipulating it to show how free moving it is.
https://www.dropbox.com/s/4bleutludp...34.31.jpg?dl=0
https://www.dropbox.com/s/2cbggq4ppp...35.02.mp4?dl=0
#2
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#4
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I thought I had it fixed, the bearing is dirty, and after 36 hours it got stuck again.
I was unable to get the bracket off after the bolt was removed the last time.
I was scared to hammer it free, but after looking at the diagram (and that it's been soaking in penetrating lube for 36 hours after assembly) should I just take a hammer to it and break it free so I can get to the bearing to clean or replace it?
for my notes: https://www.google.com/search?q=698Z...ZMC3E&safe=off
I was unable to get the bracket off after the bolt was removed the last time.
I was scared to hammer it free, but after looking at the diagram (and that it's been soaking in penetrating lube for 36 hours after assembly) should I just take a hammer to it and break it free so I can get to the bearing to clean or replace it?
for my notes: https://www.google.com/search?q=698Z...ZMC3E&safe=off
#5
AudiWorld Super User
Not sure what you are talking about hitting with hammer?
But you got to do what you gotta do to free it up.
I would think about removing the intake manifold and replacing the bearings.
I have complete intake manifold but the throttle cam is broken where the cable attaches also it is very heavy so shipping would likely be too costly.
But you got to do what you gotta do to free it up.
I would think about removing the intake manifold and replacing the bearings.
I have complete intake manifold but the throttle cam is broken where the cable attaches also it is very heavy so shipping would likely be too costly.
#6
Throttle shaft runs from the back of the manifold where the cable hooks up, to the front of the manifold (underneath the manifold), and is supported by small sealed ball bearings. These bearings lose their lube (heat), and ultimately sieze up. You can work them loose, but that is a VERY temporary repair, and it's quite dangerous to do anything but fix it correctly by disassembling the whole thing and replacing the bearings with new ones. The bearings are only a couple of bucks each, but to do it right the manifold needs to come off and be disassembled.
Been there - done that!
Good Luck,
GT
Been there - done that!
Good Luck,
GT
#7
GT,
Do you think the NSK 698ZZ is the best option for the bearing or are there others.
Bob
Amazon.com: 698zz
Do you think the NSK 698ZZ is the best option for the bearing or are there others.
Bob
Amazon.com: 698zz
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