Aloha Everyone!
I know you guys have probably seen this one many times allready, I was wondering if you guys could help me out here:
I am swapping a TBI 350 with a ZZ4 roller cam & roller rockers.
I have been told my stock computer is gonna freak out when I run this combo. Rather than put a performance chip in a worthless ECM, I'd rather have some tunibility on this one. I was told to get one of these two ECM's- 1227730 or a 1227749.
How do I convert or modify these ECM's Do you have any pictures showing the Modification? I would really appreciate the help here
p.s. my car has "Vats" if that makes any diffrence"

Thanks in Advance!!!!!!
Benjamin Smith
smithb005@hawaii.rr.com

 

Since it is your first post, I will throw you a bone here...

https://www.thirdgen.org/techbb2/sea...der=descending

There has been TONS of info posted about this, you will need the 749 ECU, along with the injector driver board from the quad4 appliction.

Are you staying TBI, or are you switching to port injection?

 

well, I'd like to stay TBI if possible, Just want to be able to run everything stock without the Factory EFI crapping the bed once I run this Huge bumpstick...... Getting the parts will not be a problem, just unsure of how to do this.
Thanks!
Ben Smith

 

I would really suggest spending time searching and reading here to start. You will find that #1, your stock 305 TBI injectors will not keep up with that motor, you are going to need larger injectors. You can tune the computer you have, many of us do. The 749 has some advantages, especial in a forced induction application, but I wouldn't say it is nescasary. The biggest obsticle to the computer you have, is its datalogging rate. You are likely not going to get many responses to this thread, the subject has been covered in depth, several times before. I would start by reading the stickies at the top of the page, and then the search results I posted earlier.

 

Thanks again, I don't really know much about electronics and programming and unless I found an individual willing to do this for me, I'll probably just go the Four Barrell intake and Carb route with an HEI distributer. I'd rather keep the TBI and maintain my EFI but I want to run a ZZ4 Cam set up, roller rockers and a stock 350 with 305 heads. (I got the whole ZZ4 setup- Cam, lifters, timing set, push rods, hardened oil pump shaft and comp cams roller rockers for $160.00 brand new, never used)
So, unless Ican find some one who has a ECM already to go for this kind of setup, or some one who is willing to help me out in modifying another ECM, I won't waste anymore of your time here.
I do appreciate the replys, don't get me wrong. I just don't want to dwell on this for a long time.
Thanks!
Ben Smith

 

That combo is going to take a lot of tuning with the TBI ECM and even more with the 7749. The 749 wasn't originally for TBI so the tune is going to be quite different than what you need, it will take some work to swap over to that ECM. If you want to get into the tuning you can tune your TBI ecm just fine, but the fuel and timing will need to be revamped for that ZZ4 setup.

 

Thanks for the Help Guys..... more trouble than I really want to deal with. This car is just my play toy and I don't care to "Tinker" with tuning that much....I don't race it and just want to be able to "stand on it" every once in a while and retain my stock electronics.
Can any of you guys tell me if simply changing a chip would allow me to drive this, albeit lack of fine tuning, but would this allow the computer to run the engine fair? just curious if anyone has done this...
Thanks!
Ben

 

Go to the TBI board for that kind of info.
Popular swap IIRC.
And, you could still use your ecm with very little research effort to control just your ignition. Much better performance wise if you can set the exact timing curve (not sloped line) that you need.
Only if you want to tinker though.
You going to need to find out all the mods needed for th tbi on the tbi board.
Doesn't sound as if your into the diy prom thing.

 

Your absolutely right....I don't want to get into a major electronics nightmare....I have someone looking into a custom Prom for me based off the mods I described to them, gave them the Duration, lift and lobe centerline of my cam, type of heads, exhaust,etc....
Hope this is the easy route, otherwise, I'm going back to Carb and HEI distributor, just don't want to have to convert my fuel system to mechanical, would rather stay EFI..... anyways, thanks for the info and have a good one!
Ben Smith

 

May want to look at the 8625 or some variant. We have conversion pinouts on forum available. Ben73 has been using with very good success so far.

 

There is no reason why you cannot run those mods with a TBI setup with a simple eprom change. If you are not also planning to convert to port injection, there really is no benefit to converting to the other ECMs IMO for the mods you have.

And, if you consider the cost to convert to port injection, a carb does look very attractive. If you do go carb, keep the existing ECM and use it to control the distributor and the converter. The ability to tune the spark curves with the ECM will give results you can never attain with a mechanical distributor.