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'82 Corvette ECM 1225550 swap to '84 Corvette ECM 1226430

KANE

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Dark Blue 1982 Trans Am(s): Polo Green 1995 MN6
So, I had read up on this swap as a way to access more diagnostic functions from commercial scan tools like my Actron unit. FYI- urban legends on some forums said it was plug and play while others had said it wasn't.

Well, it is a very simple swap and I did it in less than 20 minutes.

So yes- it is completely plug and play-
just make sure you have the right ECM (applicable transmission) and a PROM. These ECMs are can be found for around $80 or less.
 
So, I had read up on this swap as a way to access more diagnostic functions from commercial scan tools like my Actron unit. FYI- urban legends on some forums said it was plug and play while others had said it wasn't.

Well, it is a very simple swap and I did it in less than 20 minutes.

So yes- it is completely plug and play-
just make sure you have the right ECM (applicable transmission) and a PROM. These ECMs are can be found for around $80 or less.

Would be interested in what improvements you experienced. Recently swapped out my stock 82 ecm or another Cardone 82 ecm to fix some problems I had. Later others said I should have gone to the 84. Did not know it was a direct plug and play. If it is worth it, will spend the $ for an 84 ecm and new prom. But need to make sure it is worth it. BTW, 235K miles on my 82 and running good - but then repair or replace anything needed.
 
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Would be interested in what improvements you experienced. Recently swapped out my stock 82 ecm or another Cardone 82 ecm to fix some problems I had. Later others said I should have gone to the 84. Did not know it was a direct plug and play. If it is worth it, will spend the $ for an 84 ecm and new prom. But need to make sure it is worth it. BTW, 235K miles on my 82 and running good - but then repair or replace anything needed.

Hi Larry!

Sorry for taking soooooo long to get back to you. I've been slammed lately with all kinds of stuff going on.

I think the swap is worth it, especially for a stock '82. It will run better and be more consistent in operation too. The faster processor speed helps keep up with changes- and it can manage a cam and/or intake swap without throwing a code with the right chip.

If you are still interested in this swap... I have an '84 ECM with a Hypertech chip in it that I don't need. Would be very willing to let them go to a good home for much, much less than you could buy either one separately.
 
Hi Larry!

Sorry for taking soooooo long to get back to you. I've been slammed lately with all kinds of stuff going on.

I think the swap is worth it, especially for a stock '82. It will run better and be more consistent in operation too. The faster processor speed helps keep up with changes- and it can manage a cam and/or intake swap without throwing a code with the right chip.

If you are still interested in this swap... I have an '84 ECM with a Hypertech chip in it that I don't need. Would be very willing to let them go to a good home for much, much less than you could buy either one separately.

Are the connectors the same as the 82? Not interested or capable in doing any sort of rewiring.
 
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Are the connectors the same as the 82? Not interested or capable in doing any sort of rewiring.

Both harnesses use the same card reader style connectors. :thumb

It is completely plug and play... no rewiring at all. :D
 
1984 ecm to 1982

I tried this swap this week. The car started in a half a crank but idled at 1400 and would not come down. What did I do wrong. thanks JAC
 
I tried this swap this week. The car started in a half a crank but idled at 1400 and would not come down. What did I do wrong. thanks JAC
I just did a succesful swap to a 1984 ecm, in a 1982 Corvette. In my research before the swap I found the information about, that if you used the ecm for 1984 manuell transmission, you got problem with very high idle. (Yes I know the thread is old, but it's always good with information for people doing the swap in the future).
 
I just did a succesful swap to a 1984 ecm, in a 1982 Corvette. In my research before the swap I found the information about, that if you used the ecm for 1984 manuell transmission, you got problem with very high idle. (Yes I know the thread is old, but it's always good with information for people doing the swap in the future).

Been interested in this for a long time. Think you meant to say that you will have a high idle if you use the PROM for a manual. The ecm is same for automatic and manual, its the PROM that is different.
 
Been interested in this for a long time. Think you meant to say that you will have a high idle if you use the PROM for a manual. The ecm is same for automatic and manual, its the PROM that is different.
I'm not an expert, but I think they are different:
The '82 ECM is the 1225550, the 84 manual is the 1226430 and the 84 auto is the 1226026.
I bougth the 1226026 on ebay with matching prom.
 
I'm not an expert, but I think they are different:
The '82 ECM is the 1225550, the 84 manual is the 1226430 and the 84 auto is the 1226026.
I bougth the 1226026 on ebay with matching prom.

I stand corrected. You do have the correct part numbers. Looked them up on Rock Auto. I was not aware the 84 Vette had a manual transmission as well as an automatic transmission. Live and learn.
 
I stand corrected. You do have the correct part numbers. Looked them up on Rock Auto. I was not aware the 84 Vette had a manual transmission as well as an automatic transmission. Live and learn.
I hope this can explain the high idle you had.
Please let me know the result, if you do the swap in the future.
 
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Wow!! I swapped to an 84 ECM how long ago now!!?! In ‘14, I upgraded to Dynamic EFI’s EBL and moved up to a truly flexible ECM when it comes to tuning.

Back to the 84 ECM, yes, you’ll need the right chip and ECM for the transmission you have.
 
Looking at trying this on an 82 CE, having other issues and looking at a less expensive route. From what I read I must have the 84 AT prom. If I find a complete AT unit with the stock 84 prom am I good to go?

Thanks
 
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Looking at trying this on an 82 CE, having other issues and looking at a less expensive route. From what I read I must have the 84 AT prom. If I find a complete AT unit with the stock 84 prom am I good to go?

Thanks

Yes, you need both the ECM and the chip from 84, for automatic the ECM is 1226026. The electrical connectors is just to plug in. The 84 ECM is smaller than the 82, and you need to attach it in some clever way. I used zip ties as a temporary solution (I need to change that some day).
 
Cliff is a new member to this forum so I might post wrong!

I am at a crossroads as how to revive my stock '82 with a burned 1225550 ECM and burned white 24 pin female connector. This thread highly recommends upgrading to an '84 1226026 ECM with auto trans EPROM. I read that this upgrade is a plug and play swap so I am very interested. My first problem is replacing the connector that has four unrepareable pins. Can anyone tell me where to find a new/used replacement connector and '84 ECM WITH auto EPROM and follow up advice on the upgrade?
Thanks,
Cliff H.
 
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I am new to this or any forum. I have a 1982 Corvette and I'm extremely frustrated. I have replaced everything imaginable to get it running smoothly. I recently replaced the pick up coil thinking that might be the problem with my idle and why the car suddenly just dies. Well, it wasn't the problem. It starts fine and the idle seems fine, but as soon as I start to drive it, and even sometimes while still at idle, it sometimes dies. Then I pull over or just put it in neutral and it starts right back up, but then it won't drive right and even misfires occasionally. AFter a short drive and I put it in park, the idle does one of two things: it always jumps up to around 1200 rpms and about 50% of the time the idle also goes up and down as if it has a vacuum leak, which it doesn't. We can't figure it out. The only thing left is perhaps I have a bad ECM? I had Cardone rebuild one for me, but I never did know if it came out of a Vette that had an automatic or manual transmission. Any ideas what is wrong? Thanks
 

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