LT4 Idle Question
Thread Starter
Intermediate
Joined: Feb 2005
Posts: 44
Likes: 1
From: Marietta GA
LT4 Idle Question
I've just upgraded the throttle body on my LT4 to a BBK 52mm unit. I'm no experiencing a couple of problems.
First, the idle is off after the car has warmed up and the air conditioner is off. When the car first starts, the idle speed is around 600-700 RPM with the air conditioner on or off. Once the car warms up, the idle speed is still around 600-700 RPM with the airconditioner on, but 800-1000 RPM with the air conditioning off. Any ideas as to the cause? I'm thinking possibly a vacuum leak but was hoping for a little confirmation.
Second problem, the car now seems to be running hotter (~230 while idling). I think I've got this one nailed down (coolant system needs bleading). However, if anyone can tie this into the first problem and I'm way off, it'll save me a headache.
Thanks in advance for the help!
First, the idle is off after the car has warmed up and the air conditioner is off. When the car first starts, the idle speed is around 600-700 RPM with the air conditioner on or off. Once the car warms up, the idle speed is still around 600-700 RPM with the airconditioner on, but 800-1000 RPM with the air conditioning off. Any ideas as to the cause? I'm thinking possibly a vacuum leak but was hoping for a little confirmation.
Second problem, the car now seems to be running hotter (~230 while idling). I think I've got this one nailed down (coolant system needs bleading). However, if anyone can tie this into the first problem and I'm way off, it'll save me a headache.
Thanks in advance for the help!
Last edited by GACELT4; Jul 25, 2005 at 01:23 PM.
Thread Starter
Intermediate
Joined: Feb 2005
Posts: 44
Likes: 1
From: Marietta GA
Checked the throttle control arm - it rests firmly against the idle adjustment screw. I'm a newbie, but where exactly is the "button" I should push to adjust the length of the throttle cable from the ASR to the throttle body?
A little additional information - when first started the car idles where it should. However, the longer the car is run (and the hotter the car gets), the higher the idle speed creeps. After about 10-15 mins of operation the car is idling at 1k RPM's. I've got a SES light that I haven't pulled the code on yet - I'm guessing that it's the TPS sensor.
A little additional information - when first started the car idles where it should. However, the longer the car is run (and the hotter the car gets), the higher the idle speed creeps. After about 10-15 mins of operation the car is idling at 1k RPM's. I've got a SES light that I haven't pulled the code on yet - I'm guessing that it's the TPS sensor.
Le Mans Master
Joined: Jul 1999
Posts: 8,683
Likes: 6
From: Phoenix AZ
Here check this page out...a lot of aftermarket throttle bodies do not have the idle air hole drilled in them which can cause some really strange issues at idle.
http://members.***.net/chipsbyal/page/idle/index.html
http://members.***.net/chipsbyal/page/idle/index.html
