stall at idle after closed loop
Thread Starter
Drifting
Joined: Dec 2007
Posts: 1,672
Likes: 8
From: Sumter South Carolina
stall at idle after closed loop
So don't know if it was coincidence or not but I took my dash out to get refurbished and the next morning after car was warmed up the rpms dropped fast inbetween shifts and then after closed loop started it stalled if I didnt keep gasing when popping it to nuetral to slow down.
I briefly checked my vaccume lines (I don't have egr or many of them to check) the car does pop a 24 code if it almost stalls, but that is speed sensor if im not mistaken.
Could I have pulled a wire or something while removing the dash? Is the code 24 from the dash missing? If so, why does it pop when the car almost stalls and not when I start moving.
How would I check for an intake leak or runner leak (I have high flow I put on a few months back and its been fine till just now.
I briefly checked my vaccume lines (I don't have egr or many of them to check) the car does pop a 24 code if it almost stalls, but that is speed sensor if im not mistaken.
Could I have pulled a wire or something while removing the dash? Is the code 24 from the dash missing? If so, why does it pop when the car almost stalls and not when I start moving.
How would I check for an intake leak or runner leak (I have high flow I put on a few months back and its been fine till just now.
Race Director
Joined: Nov 2003
Posts: 12,221
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
Is the dash still out?
You are correct that code 24 is speed sensor. On the bottom end, that's plugged into the ZF6. On the top, I've yet to discover it's location. Probably goes to the ECM???? Or, maybe to the Atari first?
Seems like the SS would be used to monitor and determine IAC position. And, if absent, would prohibit operation of that circuit -- leading to stalling.
You are correct that code 24 is speed sensor. On the bottom end, that's plugged into the ZF6. On the top, I've yet to discover it's location. Probably goes to the ECM???? Or, maybe to the Atari first?
Seems like the SS would be used to monitor and determine IAC position. And, if absent, would prohibit operation of that circuit -- leading to stalling.
Instructor
Joined: Nov 2009
Posts: 164
Likes: 2
From: Spring Texas
Make sure you don't have a problem with the Temperature Sensor on the water pump. I had the plastic come loose from the brass base and it would make contact and drop contact. If this is failing, you should see the electronic temp on dash drop to 148 and in my case the car wold drop out of closed loop and stumble. If idling, it stalls. Good luck.
Thread Starter
Drifting
Joined: Dec 2007
Posts: 1,672
Likes: 8
From: Sumter South Carolina
Yea dash is still out of the car, I sent it to be rebuilt. It is baffling that a speed sensor would take info from other systems other than how fast is the whheel turning. Much less have power to mess with them. Why does the engine need to know the speed of the wheels? It just needs to either get louder or stop depending how hard I press the go shoe... 
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Indeed VSS comes to the ECM from the display module. I believe that the ECM increases idle speed when the vehicle is in motion; if no motion is sensed it would set the IAC to minimum position. This could account for the rapid RPM drop during a slow shift.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
