Starting my Flathead EFI build. How to ID an ECM with no label?

[1project2many]

I'd probably try to get a chip from a 2.8 or 3.1 TBI engine for backup fuel. Limp mode is programmed by resistors on the memcal. It's possible to make your own but there's a fair amount of work involved.

[kilohertz]

After a crazy busy summer, wildfires threatening our property and having to evacuate etc. I am finally getting back to flathead EFI project. Yesterday, after 6 months of searching, I finally found a 2.8L throttle body, yeah! So now I have all the components to build the EFI system this winter. I need to refresh my memory on how the whole system works before I start wiring things together.

My plan is to use the 1227747 ECM and tune it as required, but use it as is to at least get the engine running and prove everything works before I delve into reprogramming it. It has been recommended to start with the 2.8L ECM but I thought I read somewhere that you need to use an ECM from an engine with the same number of cylinders, could someone please clarify for me?

I'm sure I'll have more Q's but for now going to do more research.

Thanks and Cheers!

[MQQN28]

Hi

Ive been running efi on my flathead for ten years. My ECM is an australian delco 808. Its a 20packet. You set the no of cylinders in the BIN
Im using a gm throtal body 60mm, the 65 mm runs ok as well. The 60mm TBs here are off 3.8l v6. I would not go any lower than this.

I can give you a good timing table and VE table that will get you going.
Id suggest you set it up with an Eprom that ultraviolet erasing is a pain20161007_124931.jpg

[kilohertz]

Your engine looks great, looks like maybe MPFI?? I'm building a GM TBI system, a whole different animal, but thanks.

cheers

[joegreen]

After a crazy busy summer, wildfires threatening our property and having to evacuate etc. I am finally getting back to flathead EFI project. Yesterday, after 6 months of searching, I finally found a 2.8L throttle body, yeah! So now I have all the components to build the EFI system this winter. I need to refresh my memory on how the whole system works before I start wiring things together.

My plan is to use the 1227747 ECM and tune it as required, but use it as is to at least get the engine running and prove everything works before I delve into reprogramming it. It has been recommended to start with the 2.8L ECM but I thought I read somewhere that you need to use an ECM from an engine with the same number of cylinders, could someone please clarify for me?

I'm sure I'll have more Q's but for now going to do more research.

Thanks and Cheers!

The 1227747 ecm is just a computer to help process the data. When you customize the actual chip with tunerpro that is where you can change how many cylinders the engine has, fueling, spark etc. So im pretty sure the ecm's are the same and its the chip that dictates what engine it can run.

[kilohertz]

The 1227747 ecm is just a computer to help process the data. When you customize the actual chip with tunerpro that is where you can change how many cylinders the engine has, fueling, spark etc. So im pretty sure the ecm's are the same and its the chip that dictates what engine it can run.

Thanks Joe,

I am learning Tuner Pro a little more every day, playing with timing tables and such, can successfully program the EPROM with my EMP-20 and have all the sensors and TB unit to start building this winter.

Okay on the 747 just being a computer to process the data, but I need to ask, how does the MEMCAL fit into the picture? What is its' role? I assume it's the skinny module on the second socket next to the 2732?

Thanks

[joegreen]

Thanks Joe,

I am learning Tuner Pro a little more every day, playing with timing tables and such, can successfully program the EPROM with my EMP-20 and have all the sensors and TB unit to start building this winter.

Okay on the 747 just being a computer to process the data, but I need to ask, how does the MEMCAL fit into the picture? What is its' role? I assume it's the skinny module on the second socket next to the 2732?

Thanks

The memcal or calpack or netres whatever you want to call it is like a super basic backup chip that can run the engine if the main chip fails. Its the chip that operates the engine when its in limp home mode. I think the chip is just a bunch of resistors or something. Anyway there are a few different varieties that will run 6 cyl or 8 cyl motors ect. You will need a calpack from an 8 cyl vehicle if you want to run an 8 cyl engine.

[kilohertz]

The memcal or calpack or netres whatever you want to call it is like a super basic backup chip that can run the engine if the main chip fails. Its the chip that operates the engine when its in limp home mode. I think the chip is just a bunch of resistors or something. Anyway there are a few different varieties that will run 6 cyl or 8 cyl motors ect. You will need a calpack from an 8 cyl vehicle if you want to run an 8 cyl engine.

Okay, that explains it. I was going to ask if the limp home mode was the same as open loop settings, and after your explanation and some more research I think I understand, thanks! My 1227747 was from a 1991 5.7L truck, I should be okay to use it with the 239ci flathead.

Cheers

[kilohertz]

SUCCESS!!

I have been working on the GM TBI system as much as I can in the past month and have made some terrific progress. I machined the adapter plate for the throttle body, then polished it and mounted it on the engine. I have figured out the harness and for testing purposes have just hung it on the firewall. I am using the stock Chevy 305 ECM 1227747, just to try my ideas before I start reprogramming the internal EPROM. I bought an external fuel pump that will meet the TB requirements as I didn't want to fill the new tank with gas until I finish the fill pipe fabrication. I also had to machine another GM distributor as the TBI system uses a module and inductive pickup in the distributor. ....a video is worth 1,000 words.

More later.

Cheers

Video link

https://www.dropbox.com/s/pfm21cuj7t..._1356.mov?dl=0