Is it possible to somewhat easily use my 7747 ECU to control the spark curve when I do carb tesing on my engines???

would need:

TPS hookup on the carb = hard but riggable???
MAP signal = easy
O2 input (?) =???
IAC hookup ????
VSS = not needed
EGR, not needed
distributor = work like normal???

 

There used to be something on DIY-EFI/GMECM. I tried to find it, but could not. You might wanna try digging around in there. Ran a search on the PROM board?

 

theres an article on diy efi in the 7747 section. You really oughta check out that page sometime cuz you ask alot of questions answered there, not a flame btw.

As far as your question, I've done just that.
heres the process
Remove TBI unit
install carb
regulate pressure
plug in TPS or use a resistor so that the puter knows its there and wont trip a low tps code
drive car

pretty simple
you wont have any wot spark enable or any of that trash but it runs fine. in fact my car hauled *** like that with a holley 1850 vac secondary carb

 

So you're telling me that the ECU doesn't need TPS input and injector current flow to run spark??? Now that's just too easy. i don't really run PE advance much and you don't need it in a carb as it is usually rich at high loads and I could program the prom thusly.

I'll go to DIy and look, thanks. Just figured someone would know and I was right. thx

I also may bolt that proJection TB unit I have for sale on the motor I got. it has 85pph injectors and if I run the GM CU spark, it should tell me if I can get to 400hp if/when I can get a decent Rochester GM TB unit with 90pph injectors. this is gonna be fun! Also, want to see if I can get 400hp with a carb and ECU spark and perhaps fine-tune the spark a bit more. Although, tuning sark with carb when I am to run TBI may be a waste of time. Bored waiting for a TB, I guess. All the ones I have seen are in terible shape with shaft play, plate-to-bore interference, look rotten, etc.