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Lazy Idle (1985)

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Old 11-09-2009, 05:46 AM   #1
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Member Since: Oct 2009
Posts: 34
Default Lazy Idle (1985)

Can't figure it out. I've replaced the IAC, 02 Sensor, reset the TPS to 54 and idle according to proceedure. Cleaned the throttle body. The problem I'm having is when the car is first started the idle is around 1100 rpm. It takes around 7-8 minutes to come down to 580 rpm's. After the car is warm and been driven when you come to a stop the idle doesn't come down immediately, it takes around 15 sec after your stopped.
To me the problem appears to have the traits of a vaccume leak but I can't seem to find one (and I've looked)

Ant suggestions would be appreciated.
85 Gold
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Old 11-09-2009, 08:12 AM   #2
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Member Since: Nov 2008
Posts: 4,218
Location: Jacksonville FL

I have the same problem with my '85 and have been told that the throttle body needs to be serviced. I havent taken it off the car yet to see but I will be checking out these bushings when I clean it up.
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Old 11-09-2009, 08:55 AM   #3
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Member Since: Mar 2008
Posts: 1,994
Location: Santa Maria CA

I have the exact same problem. I'll bet if you put your foot on the brake and tap on the accelerator, the idle will come down. I've checked the throttle cable thinking it was binding. That wasn't it. So I've purchased a scanner to see if its sensor related. The hunt goes on.
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Old 11-09-2009, 10:40 AM   #4
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Member Since: May 2002
Posts: 1,500
Location: Hazel Park MI

I just installed a Holley 52MM TB, and my idle is way more steady. I noticed on my stock TB that there was some play before the spring opened the butterflies, with some slight clicking but no butterfly movement. There is none in the new TB, the butterflies open immediately upon tension. But I also got a chip retune, so I can't say the more steady idle is from the TB alone. But I think something within the stock TB was/is worn out, that's for sure.
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