93 C4 Idle speed adjustment?
Thread Starter
7th Gear
Joined: Oct 2001
Posts: 7
Likes: 0
From: Dallas TX
93 C4 Idle speed adjustment?
Last week I was driving down the freeway and when I pulled off onto the service road my idle speed was really high. I shut it down and looked under ther hood and noticed my throttle cable that goes into the ASR unit had a small plastic clamp that had broken. I noticed the cable could be twisted and it seemed to lower the idle speed so I used a steel hose clamp to secure it. That got me home. Since then it seems to run too low and I can't adjust it back. When I turn on the AC the car constantly dies and after about 20 minutes of driving it overheats. This car has been very reliable until now. What can I do???
The ASR unit has a sticker on it that states check the owners manual for throttle cable adjustment. Unfortunately I don't have one.
[Modified by Ezyrider, 10:27 AM 8/20/2002]
[Modified by Ezyrider, 10:31 AM 8/20/2002]
The ASR unit has a sticker on it that states check the owners manual for throttle cable adjustment. Unfortunately I don't have one.
[Modified by Ezyrider, 10:27 AM 8/20/2002]
[Modified by Ezyrider, 10:31 AM 8/20/2002]
Le Mans Master
Joined: Jan 2000
Posts: 6,376
Likes: 21
From: Traverse City MI
Re: 93 C4 Idle speed adjustment? (Ezyrider)
You got somne issues there:
The idle speed is controled by the Idle Air Controler. It's located on your throttle body. It is non-adjustable.
When you turn the AC on, the ECM is supposed to detect it (thru a switch I think) and increase the fuel delivery to deal with the increased load.
You car overheats in 20 minutes? I'd check coolant level, thermastat, and your fans. The fans should kick on at 230F, or whenever your AC is running.
The ASR can be adjusted, a service manual helps lots. Usually you would adjust the ASR if you are having eraditic shifting. It not a hard thing to do if you know what to do, takes about 10 minutes and you won't even get dirty.
The idle speed is controled by the Idle Air Controler. It's located on your throttle body. It is non-adjustable.
When you turn the AC on, the ECM is supposed to detect it (thru a switch I think) and increase the fuel delivery to deal with the increased load.
You car overheats in 20 minutes? I'd check coolant level, thermastat, and your fans. The fans should kick on at 230F, or whenever your AC is running.
The ASR can be adjusted, a service manual helps lots. Usually you would adjust the ASR if you are having eraditic shifting. It not a hard thing to do if you know what to do, takes about 10 minutes and you won't even get dirty.
Thread Starter
7th Gear
Joined: Oct 2001
Posts: 7
Likes: 0
From: Dallas TX
Re: 93 C4 Idle speed adjustment? (Aaron71771)
My coolant level is OK and my thermostat is working right, my secondary fan kicks on at 230F but only when the AC is on. This was never a problem until this idle thing started and now it overheats whether the AC is on or not. Of course I live in Texas and it gets really hot here but this has been a mild summer so far. Last summer was much hotter and I didn't have these problems. Thanks for your help, it is much appreciated!
Thread Starter
7th Gear
Joined: Oct 2001
Posts: 7
Likes: 0
From: Dallas TX
Re: 93 C4 Idle speed adjustment? (Aaron71771)
If I remain moving it is between 235-245F. If I sit in traffic for more than 5 min. it climbs to 260F and then gets almost to the boiling point and I have to pull over and shut it down.
Le Mans Master
Joined: Jan 2000
Posts: 6,376
Likes: 21
From: Traverse City MI
Re: 93 C4 Idle speed adjustment? (Ezyrider)
235F-245F is WAY WAY too warm for normal driving. It should hover around 200F. When stopped it should not get about 230 without the fans kicking in. Have you checked the radiator lately for debris? When was the last itme the system was flushed?
Thread Starter
7th Gear
Joined: Oct 2001
Posts: 7
Likes: 0
From: Dallas TX
Re: 93 C4 Idle speed adjustment? (Aaron71771)
I thought that was too hot. The last time I flushed it was about 8 months ago when I changed the water pump. It was fine up until the idle problem though.
Le Mans Master
Joined: Jan 2000
Posts: 6,376
Likes: 21
From: Traverse City MI
Re: 93 C4 Idle speed adjustment? (Ezyrider)
You definetly have a cooling problem. It should never get above 200ish when cruising, my 92 hoverd around 193F cruisihg and only hit 230 in the drivethru or stop and go traffic. Then the fans came on.
I would start with the thermostat, its cheap and fairly easy to replace. Also climb under the front of the car and make sure nothing is blocking the radiator, like leaves, paper, plastic etc etc.
Your Idle problem is a seperate issue, I think it's overheating with the AC just from the load and bad cooling. I can't think of how idle/cooling would be related. Too seperate systems.
Anyone else want to chime in here :confused:
[Modified by Aaron71771, 6:35 PM 8/20/2002]
I would start with the thermostat, its cheap and fairly easy to replace. Also climb under the front of the car and make sure nothing is blocking the radiator, like leaves, paper, plastic etc etc.
Your Idle problem is a seperate issue, I think it's overheating with the AC just from the load and bad cooling. I can't think of how idle/cooling would be related. Too seperate systems.
Anyone else want to chime in here :confused:
[Modified by Aaron71771, 6:35 PM 8/20/2002]
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