Engine stalls when ECM kicks in ?
Thread Starter
Heel & Toe
Joined: Oct 2025
Posts: 22
Likes: 2
Drifting
Joined: Nov 2018
Posts: 1,807
Likes: 580
From: Mays Landing, NJ
Now that he is saying its a no start it throws everything out the window. He could short pins on his OBD to see if any codes show.
Last edited by CorvetteRules; Jan 25, 2026 at 01:41 PM.
Drifting
Joined: Nov 2018
Posts: 1,807
Likes: 580
From: Mays Landing, NJ
You can check for any codes by shorting 2 pins on the OBD. On my 95 I can short pins 4 and 12, but your year is different and hopefully someone pops in to confirm what pins you need to short.
Thread Starter
Heel & Toe
Joined: Oct 2025
Posts: 22
Likes: 2
That's the idea, With its unplugged it will start and run but just lean. if it continues running when temps get to point of normal closed loop that would point to the problem being the CTS. I know this because I had same issue with the 91 L98 and suspected the CTS and that test proved it.
Now that he is saying its a no start it throws everything out the window. He could short pins on his OBD to see if any codes show.
Now that he is saying its a no start it throws everything out the window. He could short pins on his OBD to see if any codes show.
One more thought,, even if all these were wrong why would it act like its in forward and reverse at the same time ? It`s a strange sensation ,,I know that sounds nutz,,
I just ut that aside until I know the others stuff is working or not,, now to fix the no start
Burning Brakes
Joined: Aug 2008
Posts: 909
Likes: 229
From: Tampa, FL
I have a weird problem on my 1988 C4,auto, when I start her cold she fires right up and runs great and you can put her gear and she moves both forward and backwards. Once she warms to the point the ECM kicks in she runs like crap and you have to keep the throttle up high and if you put her in gear she stalls (dies) like the trans is in forward and reverse at the same time !
To restart her in park or neutral you have to hold the peddle to the floor and she will start after cranking for for a while but once again runs like crap and have to keep the RPM up or will die even when not in gear.
Now,, let her sit overnight or long enough to be bone cold and she starts up and run fine until the ECM kicks in again,,
I am lost here,, not sure what to do,,
I could find another ECM and try that but at the price of one and actually finding one that seems like just throwing parts at the problem .
Best scenario would be finding one on loan but thats almost impossible.
Any thoughts ?
To restart her in park or neutral you have to hold the peddle to the floor and she will start after cranking for for a while but once again runs like crap and have to keep the RPM up or will die even when not in gear.
Now,, let her sit overnight or long enough to be bone cold and she starts up and run fine until the ECM kicks in again,,
I am lost here,, not sure what to do,,
I could find another ECM and try that but at the price of one and actually finding one that seems like just throwing parts at the problem .
Best scenario would be finding one on loan but thats almost impossible.
Any thoughts ?
That's essentially when the engine coolant temperature reaches about 120 degrees, and / or in conjunction with the Oxygen sensor being warm enough to start reading exhaust temperatures... and then it switches over.
If your Corvette starts running like *** at that point, it means the ECM is getting improper signals from the sensors.
The primary sensors that can cause this are:
- MAP Sensor
- Coolant Temperature Sensor
- Throttle Position Sensor
... not in any particular order.
You also have a MAF sensor too, and an Intake Air Temperature sensor.
Thread Starter
Heel & Toe
Joined: Oct 2025
Posts: 22
Likes: 2
So, when you say the ECM "kicks in," the engine won't run without the ECM... so the ECM is always running. I think what you're referring to is when the engine goes into closed loop (or open loop, I always get them mixed up) mode.
That's essentially when the engine coolant temperature reaches about 120 degrees, and / or in conjunction with the Oxygen sensor being warm enough to start reading exhaust temperatures... and then it switches over.
If your Corvette starts running like *** at that point, it means the ECM is getting improper signals from the sensors.
The primary sensors that can cause this are:
- MAP Sensor
- Coolant Temperature Sensor
- Throttle Position Sensor
... not in any particular order.
You also have a MAF sensor too, and an Intake Air Temperature sensor.
That's essentially when the engine coolant temperature reaches about 120 degrees, and / or in conjunction with the Oxygen sensor being warm enough to start reading exhaust temperatures... and then it switches over.
If your Corvette starts running like *** at that point, it means the ECM is getting improper signals from the sensors.
The primary sensors that can cause this are:
- MAP Sensor
- Coolant Temperature Sensor
- Throttle Position Sensor
... not in any particular order.
You also have a MAF sensor too, and an Intake Air Temperature sensor.
Yeah , I get that, I`ll have to look at my file`s and see what I have done and replaced. this has been going on for a couple years now and I haven`t done crap for 6 months or so because I am out of patients ,, and YES,, Open loop when cold,, closed when warmed up,,
That is once I get the starter situation figured out.
Burning Brakes
Joined: Aug 2008
Posts: 909
Likes: 229
From: Tampa, FL
Yeah , I get that, I`ll have to look at my file`s and see what I have done and replaced. this has been going on for a couple years now and I haven`t done crap for 6 months or so because I am out of patients ,, and YES,, Open loop when cold,, closed when warmed up,,
That is once I get the starter situation figured out.
That is once I get the starter situation figured out.
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Pro
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Yes I am guessing as I can`t start her to find out what`s wrong,, Can`t scan if she won`t start,, It`s a two problem issue.
Now the first thing is to find out why she won`t start, then run the checks I am getting now. I do appreciate all the feed back,\.
Maybe focus on HOW to fix the NO START problem first ,,
Is it the factory security system ,, how to check
Is it the chip in the key? How to check/ bypass, I know you can find the two wires from ign switch and put a resistor in line from what i have read
Tap into the starter wire to bypass the whole system ? any idea which wire ?
ETC
Now the first thing is to find out why she won`t start, then run the checks I am getting now. I do appreciate all the feed back,\.
Maybe focus on HOW to fix the NO START problem first ,,
Is it the factory security system ,, how to check
Is it the chip in the key? How to check/ bypass, I know you can find the two wires from ign switch and put a resistor in line from what i have read
Tap into the starter wire to bypass the whole system ? any idea which wire ?
ETC
