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Possible Project 4.3L V6 in a 1994 Oldsmobile Bravada (Currently has a Carburetor after the CMPFI failed and have a TBI unit ready to go into it.)
I just had a couple questions after I've read through the manuals and the old WIKI.
So first I guess it's kind of unclear but if I retain the use of my Computer Controller 8-Pin HEI distributor, do I need to have a separate crank/cam sensor? (I haven't found mention of a cam/crank sensor in my service manual, but that doesnt mean its not there).
I saw the specific settings about setting the trigger angle and wasn't sure if that was in reference to the input for the position or not.

My next question, Which may or may not be able to be answered without opinion, but since the TBI unit itself has two injectors, how would they end up getting timed? I mean I presume they would be connected to two different I/O slots but just timed to fire at the same time.

My last question here is that I think the TBI unit uses a stepper style IAC, I read the v0.4 has better capability with driving those, but I couldn't see much on how the v0.3 would handle it. If anyone has an idea how that works or even a suggestion for which version is better let me know.

I may or may not end up going through with this right now since it has the 4L60E and I know I'll have a few headaches getting the trans to work again after a full ecu swap. (I might install it on my other car with a 3.1L V6 to maybe get some more power out of it, thats only a maybe).
If anything I'd just like to get some better fuel economy out of my daily.

Maybe just a last last question, this might be something I have to figure out on my own, but is there a way to have multiple tunes loaded in and switch between them? Like maybe a City tune, a highway tune, a perfomance tune? I don't need that ability but it would be fun to play with.
If you just need injection (you aren't clear) then there is no timed injection...

You just have it provide enough DC for what you need.

0.3 has no built in stepper motor control. You would have to make an entire external circuit for it. The 0.3 is meant for prototyping not permanent installs hence why it has screw connectors.

Also you could look at the UA4C or even the NO2C as your needs are simple.

You have 1 tune. There is no "multiple tunes" for different requirements. You tune for best performance/economy as required for each cell and you use your right foot to control how much power you get.

You are not going to want max performance at low loads while cruising so those cells you tune for best efficiency.

And you tune everything at WOT for best performance.

Multiple tunes are stupid.
One of my earliest conversions was exactly what you're doing. My goal was also primarily economy, with a boost in performance, and is exactly what I got. My path was to simply piggyback the new ECM onto the old one to steal control of fuel and ignition, while the original ECM controlled AC, cruise control, transmission, IAC, etc. For yours, you'd wire injector #1 to INJ1 and #2 to INJ2, and use 3 squirts Alternating. Later test 6/Alt, which also works great, but may limit rpm with stock injectors and pressure.

Very simple, just rerouting the ignition signal to the new ECM and intercepting the injector wires for control. The new ECM was configured with no signal bias resistors, for sharing CLT and IAT, and TPS was powered by the original ECM (feeding signal to both ECMs). I used a WBO2 that had two outputs, and fed a NB signal to the OEM ECM, and the WB to the new one. No new bungs or extra work. A single output WB controller could use a voltage divider to provide the OEM ECM with a fake perfect signal instead.

It is critical to pull power and ground from the identical points the original ECM does, so there is no supply voltage variation between them. Otherwise, you're done. Have fun!


PS: The original ECM will throw trouble codes and light the dash MIL/CEL light after a while, as it detects the fueling is not enriching when the EGR system activates. No biggie, and I simply unplugged the light, but could plug it back in anytime to read stuff if I wanted.
I want to just control the injectors and distributor for timing. IAC control would be nice but not necessary, according to PSIG.
Based on what you said theonewithin, I think the v0.4 would be better for me because I would like it to be more permanent.

I guess having one tune does make more sense, I read up on the speeduino just after looking at trans controllers that had different shift patterns so I guess I just translated that over.

I like the idea of the slimmer packages from the UA4C and the NO2C, but I guess part of the fun for me would be assembling the unit. I guess there is still some assembly with the UA4C, just not as much as the original versions.

There still is a question left here though, can my 8-pin HEI module provide the appopriate position signal for the speeduino to function?

Also, interesting idea PSIG, I have heard of problems running two PCM computers in tandem but it sounds like it can work.
My suggestion would be to take your first install in small steps, so you're not juggling too many things at once. More fun and easier to learn that way, for most people. Share what you must, and only control what you need. Perhaps just ignition first, test and tune the system, then move to fuel. Later IAC, and so on.

Not to steal any fun of assembly, but a pre-assembled board is easy and clean for this first one, and I have a feeling it will be far from your last. ;) You'll also have a much better idea of where you want to go after the first.

GM modules are fine for signals, see here: https://speeduino.com/wiki/index.php/Ha ... tor_Module
Thinking it over the past few days, I guess I'd rather have the UA4C board thats mostly assembled. It would help me out a lot getting it right.
I think you have a good point taking it one step at a time, especially with my already somewhat funky setup. I could even leave my carburetor on it while I get to installing the computer and control the ignition timing for the carbureted setup.
Thanks for the advice PSIG!

Also you're probably right about this not being my last, my other car is definitely due to have some sort of tune put on it. I know it has a lot of power capability but its just gotta be unlocked!

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