1970 CUDA - 6.4L GEN III Engine SWAP - WOT Issues

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Diego García

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Sep 14, 2020
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Location
Buenos Aires, Argentina
Hi everybody. I'm writing here looking for some help.
I installed a 6.4 GEN III Engine (SRT 8 392/485 HP 6.4L Gen 3 Factory Assembly Line Engine - Bouchillon Performance Engineering) with a Computer Management Kit in my 1970 Cuda, all brand new.
The engine starts and idle fine, but as soon I try to accelerate to WOT the engine couldn't hold the RPMs and comes down, when I try to accelerate againt it hessitates. It looks like a fuel cut or lack of fuel pressure, but the fuel pressure is 60 psi constant.
I checked for DTCs, but none is present.
Does anybody here have a similar issue and could help me with some clue where to start?

WhatsApp Image 2020-09-13 at 12.43.37.jpeg
 
I'd start with Bouchillon, and talk to Randy. They have always had good customer service, and may know what it is. One of the sensors may be bad around the throttle body, MAF, TPS, etc. Good luck...and you have a nice Cuda!
 
Do you have drive by wire throttle. You may need to learn the pedal position. Disconnect battery, reconnect hold down on pedal and turn key to on. Let off pedal turn key to on and then to start
 
It also sounds like your transmission is in limp mode if you are using a computer controlled transmission.
 
What transmission do have. Do you have any vacuum leaks. Beautiful Cuda by the way. Post a pic of the 6.4 in there. We like to see all the realestate those Ebodies have.
 
I'd start with Bouchillon, and talk to Randy. They have always had good customer service, and may know what it is. One of the sensors may be bad around the throttle body, MAF, TPS, etc. Good luck...and you have a nice Cuda!

Thanks for your help! Yes, I'm talking with Randy and he allways give us good support. In the meantime, I posted this thread to have additional ideas.
 
Do you have drive by wire throttle. You may need to learn the pedal position. Disconnect battery, reconnect hold down on pedal and turn key to on. Let off pedal turn key to on and then to start

Hi, thanks for your help. Yes, it is a drive by wire throttle. We did the learn procedure that you described above, but it didn't solve the problem. On the other hand, I found an Instruction Sheet from MOPAR that explaine the Pedal Learn process as follow:

Pedal Learn Visit a MOPAR dealer to perform the pedal learn function below:
1. Connect a battery charger to the vehicle.
2. Cycle ignition to RUN.
3. Connect the scan tool (wiTECH 2.0).
4. Enter VIN as “11111111111111111”.
5. Select “2015” and “LA” (Challenger) as vehicle from drop down menus.
6. Select “PCM.”
7. Select “Misc Functions.”
8. Select “Learn ETC.”
9. Follow on-screen instructions.
10. Cycle ignition key after the successful routine completion.

I'm trying to buy the wiTECH scanner (I'm from Argentina) and then perform these steps.
 
What transmission do have. Do you have any vacuum leaks. Beautiful Cuda by the way. Post a pic of the 6.4 in there. We like to see all the realestate those Ebodies have.

Thanks, it was a really nice restoration project! The car has a T56 6 speed manual transmission. We double-checked all vacuum lines and ports and threre are no leaks.

WhatsApp Image 2020-09-15 at 12.56.05.jpeg
 
I recorded a video, in which you could listen the engine failure. I hope it helps. Thank to all!
it looks as though you are hitting your rev limiter. Maybe your computer won’t allow so many times before it cuts out. Send an email to Bouchilon if you can’t call them. Does that happen when you drive it or is it only at WOT it neutral
 
it looks as though you are hitting your rev limiter. Maybe your computer won’t allow so many times before it cuts out. Send an email to Bouchilon if you can’t call them. Does that happen when you drive it or is it only at WOT it neutral

Hi logancuda, thanks for your support! The problem shows up even cruising at 2.500 RPM. The engine begis to hesitate and loss power. I'm talking with Randy, he suggested me to do the Pedal Learn procedure with an scanner, I just bought the wiTech Micropod and I will try to apply this procedure in a couple of days (due to COVID we've some logistics issues). I'll back with the results. Thanks!
 
Finally I bought the Witech 2.0 scanner and tried to connect to the ECU, but the software show me the following error message and I can't access to any menu to do the Pedal learn procedure. Could you give me some advice? As you can see in the pictures bellow, the scanner complete de connectivity procedure but can't access to the ECU. Could be a damage ECU?

Non-responsive ECU 2.png


Non-responsive ECU.png
 
Finally I bought the Witech 2.0 scanner and tried to connect to the ECU, but the software show me the following error message and I can't access to any menu to do the Pedal learn procedure. Could you give me some advice? As you can see in the pictures bellow, the scanner complete de connectivity procedure but can't access to the ECU. Could be a damage ECU?

View attachment 1715602561

View attachment 1715602562
I just remembered I had a similar problem with mine. 1 of many. It was a ground problem. The trans ground was loose and my battery was in the trunk and I had to add a ground from the battery the chassis(bumper bracket bolts). You may need more grounds.
 
I just remembered I had a similar problem with mine. 1 of many. It was a ground problem. The trans ground was loose and my battery was in the trunk and I had to add a ground from the battery the chassis(bumper bracket bolts). You may need more grounds.

I checked the ground a couple of times, due to the original error, but I'll do again and I let you know if something change. Thanks!
 
Hi Everybody,
A couple of hours ago, following a Randy suggestion, we connected an additional positive battery wire directly to the PCM, and finally the engine is working fine!!

Thanks all for your help!
 
Hi Everybody,
A couple of hours ago, following a Randy suggestion, we connected an additional positive battery wire directly to the PCM, and finally the engine is working fine!!

Thanks all for your help!
That’s great news. I thought for sure is was a ground not a positive feed. Good deal. Have fun with that car looks fantastic.
 
Wow! Great news!
Looking forward to another video. Driving of course!
 
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