ECM Delete
Thread Starter
Instructor
Joined: Jun 2019
Posts: 232
Likes: 14
ECM Delete
Ed's topic/questions of the day.
As I'm reading the shop manual about the Computer and what it monitors and controls, I notice that the neutral safety appears to give input. I know the ECM also controls the converter lock up.
When disconnecting all the sensors, etc..., will I get a check engine light? If I disconnect the connectors to/on the ECM, will that prevent the check engine light from coming/staying on? I'm assuming that when I pull the connectors to the ECM, one wire in the plug is power to the ECM.
As I understand it, the trans will work fine, but will not lock up at higher speeds, resulting in some mpg loss. I've been told by the local trans shop that they can fix the trans to hydraulically lock up.
Can those who have deleted the ECM please share your experience and suggestions, especially about the affect on the neutral safety (if any) the check engine light, and pulling the plugs off the ECM? TIA!
As I'm reading the shop manual about the Computer and what it monitors and controls, I notice that the neutral safety appears to give input. I know the ECM also controls the converter lock up.
When disconnecting all the sensors, etc..., will I get a check engine light? If I disconnect the connectors to/on the ECM, will that prevent the check engine light from coming/staying on? I'm assuming that when I pull the connectors to the ECM, one wire in the plug is power to the ECM.
As I understand it, the trans will work fine, but will not lock up at higher speeds, resulting in some mpg loss. I've been told by the local trans shop that they can fix the trans to hydraulically lock up.
Can those who have deleted the ECM please share your experience and suggestions, especially about the affect on the neutral safety (if any) the check engine light, and pulling the plugs off the ECM? TIA!
Race Director
Joined: Jul 2004
Posts: 12,672
Likes: 329
From: Scottsdale Arizona
I’m not certain if you CEL will come on if the computer is removed. I suspect not. Easy to check though, just unplug it.
If you remove the computer, losing lockup is the least of your concerns. You’ll have to replace the distributor or you won’t get any advance. You’ll also have to replace the carb. Both are controlled by the CCC.
If you remove the computer, losing lockup is the least of your concerns. You’ll have to replace the distributor or you won’t get any advance. You’ll also have to replace the carb. Both are controlled by the CCC.
Thread Starter
Instructor
Joined: Jun 2019
Posts: 232
Likes: 14
I know that I must replace the dist and computer. Still trying to get that aspect straight. Originally planned on an Edelbrock 1406 carb on an Edelbrock 2101 intake and an HEI dist. Edelbrock tech says that a 2701 intake won't fit under corvette hood, yet many on other forums say they have it and it works fine?? Now, looking at using stock intake and putting a Holley 4175, which is advertised as a Qjet replacement. I'm not looking for much, if any, of a boost in hp, but want to find one that fits under the hood. I'm getting a ton of conflicting advice about set ups. Which intake, carb, and air cleaner combination will fit under a stock '81 hood?
Drifting
Joined: Jun 2012
Posts: 1,990
Likes: 183
From: Port St. Lucie Fl
The ecm does control lock up, so you will need to move that to a manual switch or a vacuum switch from Summit you can install this yourself and is adjustable to your liking.
The Ecm may control timing, it is possibly you may need a different dist.
The ecm definitely used the carb for input removing ecm may affect the way it runs.. Replace carb.
intake manifold may or may not have provision for choke and require a quadrajet replacement. New intake will resolve the coke issue and may also be needed for new carb pattern.
unplugging the ecm should stop any ecm related CEL.
lock up is required on the 700r4. When in over drive the pump stops pumping the fluid to make the engine more efficient, allowing the convertor to slip causes heat and has no way to dissipate the heat resulting in a burnt up trans.
The Ecm may control timing, it is possibly you may need a different dist.
The ecm definitely used the carb for input removing ecm may affect the way it runs.. Replace carb.
intake manifold may or may not have provision for choke and require a quadrajet replacement. New intake will resolve the coke issue and may also be needed for new carb pattern.
unplugging the ecm should stop any ecm related CEL.
lock up is required on the 700r4. When in over drive the pump stops pumping the fluid to make the engine more efficient, allowing the convertor to slip causes heat and has no way to dissipate the heat resulting in a burnt up trans.
Dr. Detroit
Joined: Mar 2012
Posts: 10,090
Likes: 4,015
From: New Braunfels Texas
The ecm does control lock up, so you will need to move that to a manual switch or a vacuum switch from Summit you can install this yourself and is adjustable to your liking.
The Ecm may control timing, it is possibly you may need a different dist.
The ecm definitely used the carb for input removing ecm may affect the way it runs.. Replace carb.
intake manifold may or may not have provision for choke and require a quadrajet replacement. New intake will resolve the coke issue and may also be needed for new carb pattern.
unplugging the ecm should stop any ecm related CEL.
lock up is required on the 700r4. When in over drive the pump stops pumping the fluid to make the engine more efficient, allowing the convertor to slip causes heat and has no way to dissipate the heat resulting in a burnt up trans.
The Ecm may control timing, it is possibly you may need a different dist.
The ecm definitely used the carb for input removing ecm may affect the way it runs.. Replace carb.
intake manifold may or may not have provision for choke and require a quadrajet replacement. New intake will resolve the coke issue and may also be needed for new carb pattern.
unplugging the ecm should stop any ecm related CEL.
lock up is required on the 700r4. When in over drive the pump stops pumping the fluid to make the engine more efficient, allowing the convertor to slip causes heat and has no way to dissipate the heat resulting in a burnt up trans.
Jebby
Drifting
Joined: Jun 2012
Posts: 1,990
Likes: 183
From: Port St. Lucie Fl
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Dr. Detroit
Joined: Mar 2012
Posts: 10,090
Likes: 4,015
From: New Braunfels Texas
TCI and B&M have lockup switch kits that mount the switch to the carb I believe.....
I wired a toggle on my 82’ CrossFire Camaro when I deleted the CFI.....it worked great but you HAVE to make sure you shut it off before you get off the highway and stop or it will shudder...and stall the engine...
Jebby
I wired a toggle on my 82’ CrossFire Camaro when I deleted the CFI.....it worked great but you HAVE to make sure you shut it off before you get off the highway and stop or it will shudder...and stall the engine...
Jebby
Drifting
Joined: Jun 2012
Posts: 1,990
Likes: 183
From: Port St. Lucie Fl
TCI and B&M have lockup switch kits that mount the switch to the carb I believe.....
I wired a toggle on my 82’ CrossFire Camaro when I deleted the CFI.....it worked great but you HAVE to make sure you shut it off before you get off the highway and stop or it will shudder...and stall the engine...
Jebby
I wired a toggle on my 82’ CrossFire Camaro when I deleted the CFI.....it worked great but you HAVE to make sure you shut it off before you get off the highway and stop or it will shudder...and stall the engine...
Jebby
Dr. Detroit
Joined: Mar 2012
Posts: 10,090
Likes: 4,015
From: New Braunfels Texas
Jebby
Instructor
Joined: May 2019
Posts: 156
Likes: 18
From: East Tennessee
I have eliminated my computer on my '81 with a new distributor and carb too.
Would you care to elaborate on the process of wiring into the cruise circuit? Diagrams? Links? I have searched, but my search-fu is lacking.
Thanks in advance!
I will start a new thread for this if that is prudent and polite.
Last edited by Puniphorous; Jul 30, 2019 at 09:51 PM.
Drifting
Joined: Jun 2012
Posts: 1,990
Likes: 183
From: Port St. Lucie Fl
Sorry to butt into a thread...
I have eliminated my computer on my '81 with a new distributor and carb too.
Would you care to elaborate on the process of wiring into the cruise circuit? Diagrams? Links? I have searched, but my search-fu is lacking.
Thanks in advance!
I will start a new thread for this if that is prudent and polite.
I have eliminated my computer on my '81 with a new distributor and carb too.
Would you care to elaborate on the process of wiring into the cruise circuit? Diagrams? Links? I have searched, but my search-fu is lacking.
Thanks in advance!
I will start a new thread for this if that is prudent and polite.
locate the terminal on the cruise side of the switch that loses power when brakes are applied. (this is your power source for trigger wire) wire to lock up plug.
route ground of trigger wire to manual switch, then ground manual switch
run ignition hot fused + 12v power to lock up connector
route - 12v ground from lock up connector to ground.
Last edited by Kacyc3; Jul 31, 2019 at 12:36 PM.