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I'm looking into tuning my 1984 C4 Corvette, if I am correct in this year the ecm is not very tunable. I was thinking about putting a newer ecm in the Corvette from a truck of that same era. This way I can tune the engine to give it better performance. The engine is a new 383 that I built for it. Since it is a 84 it has the Crossfire Injection System, I like this because it is unique, but I know they can be a hassle. So I was wandering if putting a newer ecm from a truck would work and what else would I have to do along this the new ecm. For the new ecm I was thinking between a 1994, 1995, a 7427. I am 14 so pretty new to the computer side of cars and tuning so any help would be amazing.
From: Liliha Bakery stuffing my face with coco puffs!
Let's start with you wouldn't be the first to do this...I can't remember the screen name of the person who's done it (ben73) but I'm sure he'll chime in. Your stock computer will have connector ends that plug into this...
...the '7427 will look like this...
...someone sells an adapter that will help adapt your stock harness to the "newer" ECM. Re-pinning is still required as well as deleting the ESC module and changing the 100k knock sensor to a 3.9K. Equipment to tune most definitely a bonus. i.e. laptop, data cable, tuning software, PROM chips, burner, memcal chip adapter etc.
I'll let others chime in to make the CF intake to breathe more...
Last edited by stew86MCSS396; Mar 20, 2025 at 05:51 PM.
Let's start with you wouldn't be the first to do this...I can't remember the screen name of the person who's done it (ben73) but I'm sure he'll chime in. Your stock computer will have connector ends that plug into this...
...the '7427 will look like this...
...someone sells an adapter that will help adapt your stock harness to the "newer" ECM. Re-pinning is still required as well as deleting the ESC module and changing the 100k knock sensor to a 3.9K. Equipment to tune most definitely a bonus. i.e. laptop, data cable, tuning software, PROM chips, burner, memcal chip adapter etc.
I'll let others chime in to make the CF intake to breathe more...
that's dynamic EFI- EBL FLASH II EMC. not available at the moment. should be in the futures.
I am looking for something that I can hop in and drive without worrying that it will quit, but also am interested in some auto cross events. Sorry for the late reply life's been busy but now that school is out I should be able to start working on it consistently.
I'm looking into tuning my 1984 C4 Corvette, if I am correct in this year the ecm is not very tunable. I was thinking about putting a newer ecm in the Corvette from a truck of that same era. This way I can tune the engine to give it better performance. The engine is a new 383 that I built for it. Since it is a 84 it has the Crossfire Injection System, I like this because it is unique, but I know they can be a hassle. So I was wandering if putting a newer ecm from a truck would work and what else would I have to do along this the new ecm. For the new ecm I was thinking between a 1994, 1995, a 7427. I am 14 so pretty new to the computer side of cars and tuning so any help would be amazing.
To the OP, Elijah, 100% go for it. You can find the recipe to hog out the manifold, u can get 454 truck injectors from the junk yard, and put an 85 pump (cheap, just the pump, not the whole sending unit) to boost your pressures.
The 84 Corvette represents on of the last holdouts of cars for first timers that has huge potential for almost no money.
Find the harness that plugs into the 7427, cut off the harness a fair ways back to allow you to solder the 84’s harness to the proper pin. Thats how i would handle it. This is an almost free solution for you.
Tunerpro rt is free, all you need is a chip (i actually dont know what those blanks cost) and you can tune your 84 383.
I love it. my daughter(s) have an 84 4+3 they have been slowly fixing up with help from this community and its now almost ready to paint.
Lets see some pics Elijah. You are 14 and im stoked your are here posting this. Good luck to you.
wait, cant we just program the truck ecm with tunerpro rt?
Only after buying a stack of chips, and hardware to link up Tunerpro to said chips, try a tune, discover it's worse, burn a new chip. Oops, forgot to change something, burn a chip....
The EBL has flash memory so you could just rewrite it at will vs going thru chips and hoping the tune copied cleanly to the chip
Years ago I had a 383 in my 84 and I kept the CFI. I swapped in a 7747 ECU out of a throttle body truck. It worked but it was a pain in the ***. A forum member @Dominic Sorresso helped me with the tune. He made me a few chips to get me started. This was 20 years ago. But every change you want to make requires you to burn a new chip. Yes you can erase them and write over them. But you need to erase them with a UV light. It's not a quick process. For the amount of time you would have in it in today's day in age an aftermarket ECU is the way to go. There are a lot of good budget options now that are so much easier to work with than a 7747. Also you get a lot of online support in writing a tune to help.
Only after buying a stack of chips, and hardware to link up Tunerpro to said chips, try a tune, discover it's worse, burn a new chip. Oops, forgot to change something, burn a chip....
The EBL has flash memory so you could just rewrite it at will vs going thru chips and hoping the tune copied cleanly to the chip
What do you mean by EBL? That sounds like a much better solution than writing a whole bunch of chips, or erasing with a UV light.
Years ago I had a 383 in my 84 and I kept the CFI. I swapped in a 7747 ECU out of a throttle body truck. It worked but it was a pain in the ***. A forum member @Dominic Sorresso helped me with the tune. He made me a few chips to get me started. This was 20 years ago. But every change you want to make requires you to burn a new chip. Yes you can erase them and write over them. But you need to erase them with a UV light. It's not a quick process. For the amount of time you would have in it in today's day in age an aftermarket ECU is the way to go. There are a lot of good budget options now that are so much easier to work with than a 7747. Also you get a lot of online support in writing a tune to help.
Do you happen to have some sources or links to those aftermarket ECU's? And are they plug and play units?
I currently have access to an Autoprom Chip burner and some chips. 2-32 pin chips and 2-28 pin chips.
And I have a 16196395 ECU from a '95 TBI 350 4x4 Chevy Truck. I think this is very similar if not the same as the 7747 ECM.
Thoughts?
Last edited by Elijah Puttmann; Jun 4, 2025 at 01:30 PM.
My suggestion is to go spend time on thirdgen.org. EBL would be the easiest conversion although unfortunately the creator Robert Rauscher passed away. U may be able to find a used EBL. If ur building a Xfire for more power, u’ll need to use a VAFPR to vary fuel pressure for proper idle up thru WOT conditions. EBL handled that for me. 3rdgen has a total forum devoted to tuning w EBL.
Do you happen to have some sources or links to those aftermarket ECU's? And are they plug and play units?
I currently have access to an Autoprom Chip burner and some chips. 2-32 pin chips and 2-28 pin chips.
And I have a 16196395 ECU from a '95 TBI 350 4x4 Chevy Truck. I think this is very similar if not the same as the 7747 ECM.
Thoughts?
If you want something that won't cost a lot then I would start here.
No it's not plug and play. You will have to either make/buy a harness or make a harness adapter. But this is way easier than using a old ECU from a truck. It will also let you data log and use a wide band o2.
1984 Corvette Tuning
