86 Throttle Body Sticking
Thread Starter
Racer
Joined: Aug 2009
Posts: 496
Likes: 4
From: Cordova TN
86 Throttle Body Sticking
I did the injectors a few weeks ago and cleaned out the plenum, runners and throttle body. Ever since I put everything back I have had problems with idle. I changed out the IAC a couple of weeks ago and finally got around to doing the IAC and TPS check today. I followed everything on the IAC setting(24 years and nobody had ever adjusted it since the plug was still in) and got the idle in park to 450. I then rehooked the IAC and it idled great at 6-7. Just sat there. Then I hit the pedal a few times and it didn't come back to 6 or 7 but pumped up to either 9 or 12. I checked out the throttle body and found that it would stick before coming back to the stop screw. I pushed the TN back against the set screw and the idle was back to 6-7. Any ideas on how to get it to swing back or am I looking at a worn out TB? Could the TPS be the reason it is sticking?
Thanks for any help.
Thanks for any help.
Burning Brakes
Joined: Aug 2010
Posts: 833
Likes: 1
I've got the very same problem on my 86. It only sticks when the engine is running, and returns against the stop screw perfectly when it is not running. Odd... Unhook all the cables from the throttle arm, and using your hand, rev the engine and see if it still sticks. Mine does it even with all the cables off.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
The engine vac pulls the butterflies off center so they hang up on the bores unless the pedal is given a tap to seat them closed
Thread Starter
Racer
Joined: Aug 2009
Posts: 496
Likes: 4
From: Cordova TN
Before I spend the money on a new 52mm TB I am going to make sure the inside is well lubed thinking maybe when I cleaned it out during the injector install I dried it out a bit too much. What could I use to lube the inside of the TB?
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Burning Brakes
Joined: May 2010
Posts: 900
Likes: 3
From: Cary illinois
Bushings are worn .
I boughta rebuilt unit from extreme fi . Been waiting over a month for my core refund . Seller wont call me back .
If you deal with these f--king people dont expect a core refund .
Ill retract the statement if I get my money .
I boughta rebuilt unit from extreme fi . Been waiting over a month for my core refund . Seller wont call me back .
If you deal with these f--king people dont expect a core refund .
Ill retract the statement if I get my money .
Last edited by Rob31; Oct 19, 2010 at 12:10 PM.
Drifting
Joined: Aug 2010
Posts: 1,704
Likes: 8
http://www.corvetteitalia.it/forum/t...TOPIC_ID=13087
http://www.corvetteitalia.it/forum/t...TOPIC_ID=13087
LOTS OF PICS Hi guys,i know this is in Italian but this thread in ours Corvette Italia forum is a fantastic source for who is a real DIY man.This guy make a total throttle body rebuil showing us that in most cases everythings must be reconditioned.I must admit it, Michele,this is his name, uses father's machinist shop tools to do this job, btw results are great.He went through a total diassemble, particulaly he wanted to solve a throttle shaft play issue.worn shaft have play issue,he performed a bore shaft honing,inserting new metal bushing to compensate metal honing,he have honed to 50mm throttle blades bore,then replaced with new 50 mm plates.Probably this job is worth more for personal satisfaction than for a real budget saving,but, as i say it was a real pleasure to have all done by yourself...
http://www.corvetteitalia.it/forum/t...TOPIC_ID=13087
LOTS OF PICS Hi guys,i know this is in Italian but this thread in ours Corvette Italia forum is a fantastic source for who is a real DIY man.This guy make a total throttle body rebuil showing us that in most cases everythings must be reconditioned.I must admit it, Michele,this is his name, uses father's machinist shop tools to do this job, btw results are great.He went through a total diassemble, particulaly he wanted to solve a throttle shaft play issue.worn shaft have play issue,he performed a bore shaft honing,inserting new metal bushing to compensate metal honing,he have honed to 50mm throttle blades bore,then replaced with new 50 mm plates.Probably this job is worth more for personal satisfaction than for a real budget saving,but, as i say it was a real pleasure to have all done by yourself...
Last edited by tunedport85inject; Oct 3, 2010 at 08:44 AM.
Thread Starter
Racer
Joined: Aug 2009
Posts: 496
Likes: 4
From: Cordova TN
Anybody have any experience with this one...
http://www.jcwhitney.com/gm-throttle...41&zmap=604591
$100 less than the ones that Jegs is selling. Glad I read about the extreme fi. I was thinking of buring a rebuilt one but not worth it if this one at Whitneys is a good one.
http://www.jcwhitney.com/gm-throttle...41&zmap=604591
$100 less than the ones that Jegs is selling. Glad I read about the extreme fi. I was thinking of buring a rebuilt one but not worth it if this one at Whitneys is a good one.
Thread Starter
Racer
Joined: Aug 2009
Posts: 496
Likes: 4
From: Cordova TN
Nobody have any experiences with this throttle body? I have read about problems with the other ones costing $100 more so I would like to hear from someone who has purchased one of these.
Cruising
Joined: Sep 2010
Posts: 14
Likes: 0
From: Philadelphia Pennsylvania
I ordered a BBK 52mm for $270 from some online parts monster. Wish I had seen that one before I ordered mine. I'm curious to see how yours performs. When are you expecting it to be installed?
Thread Starter
Racer
Joined: Aug 2009
Posts: 496
Likes: 4
From: Cordova TN
I just ordered it today after reading some good reviews over on thirdgen.org about the performance products throttle body. Hoping to have it here in a week or so and I'll swap them out asap. I'll let everyone know how it performs. Right now with the new injectors the throttle response is incredible but the idle sucks with it sticking all the time.
Thread Starter
Racer
Joined: Aug 2009
Posts: 496
Likes: 4
From: Cordova TN
I got the TB last Thursday and started installing it this weekend. Everything was easy and straight forward until I got the final step. Reinstalling the duct between the TB and the MAF sensor. I slit the duct and heated it and still couldn't get it to fit onto the TB. I am now waiting for a rubber duct from mamo that supposedly will either fit the TB or be easier to stretch with a little heat to get it to fit. So another $45 spent on it but from what I have read here the other 52mm new TBs have the same problem.
It also ended up being a good time to replace allllll of that 1/8" vacuum tubing. It cracked as I was trying to remove the water hose to the TB. That vacuu tubing was all toast and cracked into pieces.
As far as the quality of the TB I would give it an A. I haven't found anything wrong with it so far and the switch over of the linkage was simple. I'm hoping to find no problems once I get the duct and install it and crank the car up.
It also ended up being a good time to replace allllll of that 1/8" vacuum tubing. It cracked as I was trying to remove the water hose to the TB. That vacuu tubing was all toast and cracked into pieces.
As far as the quality of the TB I would give it an A. I haven't found anything wrong with it so far and the switch over of the linkage was simple. I'm hoping to find no problems once I get the duct and install it and crank the car up.
Advanced
Joined: Apr 2005
Posts: 77
Likes: 0
From: South Brunswick New Jersey
Based on this tread, I also purchased this throttle body from JCW. I tried installing it last night and exactly the same problem. I couldn't for the life of me get the intake duct over the throttle body. I ended up putting my old TB back on for now. Wasn't sure if I should try to modify a replacement duct or to mill down the TB opening to make the duct fit. Please let us know how you make out!
Thread Starter
Racer
Joined: Aug 2009
Posts: 496
Likes: 4
From: Cordova TN
I would stear clear from trying to file the TB. Hold up your old one in front of the new one from JCW. There is a bigger difference than just a little lip some have filed off. I'll let you know how the rubber replacement duct works out.
