Rough Idle Questions
Thread Starter
1st Gear
Joined: Oct 2025
Posts: 1
Likes: 0
Rough Idle Questions
I have a 85 automatic and it’s come up with a code 32 and code 43. When I cold start the car it idles at 1000 and then sharply drops down to 500 and then jumps up and down till it eventually dies. If I get it driving it’ll will idle at around 550rpm. I’ve done a little bit of research and I’ve tested to see if there’s continuity on the egr temp switch and that showed up good. Any help or info would be greatly appreciated. Thanks in advance - Brody
Pro
Joined: Jul 2023
Posts: 533
Likes: 278
From: Marysville WA
Code 32 usually EGR valve or MAP sensor related issue. Both are part of the vacuum system. I replaced all vacuum lines and the EGR valve on my '84 and solved issues similar to what you are experiencing.
Vacuum leaks are VERY common on early C4's.
Code 43 is ESC module or more likely the knock sensor on the bottom of the block. There are electrical tests you can run to confirm correct voltage from the sensor.
Do you have a factory service manual (FSM)? The specific test routines are spelled out in detail there.
https://www.rockauto.com/en/moreinfo...=10335&jsn=503
Vacuum leaks are VERY common on early C4's.
Code 43 is ESC module or more likely the knock sensor on the bottom of the block. There are electrical tests you can run to confirm correct voltage from the sensor.
Do you have a factory service manual (FSM)? The specific test routines are spelled out in detail there.
https://www.rockauto.com/en/moreinfo...=10335&jsn=503
