C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Lazy Idle (1985)

Old 11-09-2009, 05:46 AM
  #1  
hln111
Intermediate
Thread Starter
 
hln111's Avatar
 
Member Since: Oct 2009
Posts: 34
Likes: 0
Received 0 Likes on 0 Posts
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
Old 11-09-2009, 08:12 AM
  #2  
HlhnEast
Safety Car
 
HlhnEast's Avatar
 
Member Since: Nov 2008
Location: Jacksonville FL
Posts: 4,328
Received 14 Likes on 14 Posts
Default

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.
Old 11-09-2009, 08:55 AM
  #3  
cumbercr
Melting Slicks
 
cumbercr's Avatar
 
Member Since: Mar 2008
Location: Santa Maria, CA
Posts: 2,141
Received 66 Likes on 45 Posts

Default

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.
Old 11-09-2009, 10:40 AM
  #4  
jmrl98
Drifting
 
jmrl98's Avatar
 
Member Since: May 2002
Location: Hazel Park MI
Posts: 1,508
Received 3 Likes on 2 Posts

Default

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.

Get notified of new replies

To Lazy Idle (1985)



Thread Tools
Search this Thread
Quick Reply: Lazy Idle (1985)



All times are GMT -4. The time now is 04:54 AM.