8747 ecm - th400 to 700r4

Hey all, I've searched around and found SOME info on this scenario but nothing clear cut. I've been reading through a thread about a guy doing the opposite. I received a free 350 tbi engine from my brother that he had in a Jeep CJ8. As far as he knows, it is a stock 350 tbi from a 89' GMC Sierra, bored .030 over, with a howell universal wiring harness and fuel pump. I still have his jeep around to pull ALL the parts should I have missed any. My biggest concern is the tranny swap. I'm taking the motor from him but not his transmission as it's 4x4, mine is a 700r4. The ecm is a '8747. It is setup to control his th400 kickdown. How would I go about making it control the TCC in my 700r4? I'm likely ordering a chip burner very soon. I thought about going EBL, but I have many friends that love to retro build, and figure getting a chip burner and LEARNING how to tune vs. using a EBL to do it all for me is a better idea. So with that, would you guys recommend I just go buy a 7747 ecm? Would it make my life that much easier? please no suggestions about the 7727 or whatever the newer ecm is. I'ld like to be able to utilize the wiring harness without hacking anything apart and from my reading, it's possible going from 8747 to 7747. Also, not of huge concern, but would you guys recommend getting the EBL in my case? Or learning how to tune? I have plenty of time to learn as this car is a project, not a daily driver.

I think I would, if it was my project, go with the '7747 ECM. I would use a Vehicle Speed Sensor (VSS) because of the 700R4 TCC controls require the VSS! I'm thinking there will be a need to add some wiring for the 700R4 TCC, because the '8747 did not have 700R4 TCC wiring? The EBL has some advantages, no chips and better spark / fuel tables than the '7747. For the money, the '7747 is the budget option.

dave w

Thanks for the suggestion. I'll have to keep my eye out for a 7747 ecm. I did notice however in the HAC files for the $4F for AKWA.bin there is entries for TCC, but I don't see any of the options available in tunerpro. Would these be possible to add or is that more complex than I'm able to deal with being a noob to all this.

You could always learn! Your already reading a hac so that far more then most already. Little warning on hacs though, all the comments are from humans, the hex code is usually sound, comments? It may be comments from another hac in there. All the C3 ECM share a lot of code. But the 8747 never came on 700R4 and 7747 never came with TH400. But both are just one circut to do one thing, Th400 kickdown and 700R4 TCC lockup... it would be an experiment. Dave has done 700R4 to TH400 with 7747 IIRC?

7747 $42 will plug in and XDF code is complete. I wouldn't try anything else unless I was bored...

I just wanted to point out that the EBL doesn't "do everything for you" as in tune itself. Yes, it has an "autotune" feature, but that strictly does the VE table(s). Everything else, spark, warm up, and many other things still need manual interaction to get tuned in.

'7747 would be the easiest option.

Quote:

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Originally Posted by EagleMark

Dave has done 700R4 to TH400 with 7747 IIRC?

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There is the option of using an Accelerator Pedal mounted TH400 Kick Down Switch to control the TH400 kick down. Look at post #56 for the details

dave w

http://www.gearhead-efi.com/Fuel-Inj...ections!/page4