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

Hi guys,

I am starting to gather parts for a fuel injection build on my '49 Ford Flathead engine which is in my old F-1 truck. I am planning on using the GM TBI injection system and have been reading and studying the various systems over the last month or so. I am an electronics tech so there will be a small learning curve for me to understand how programming and tuning and such is done, but at this point I need to get all the basics together.

So my neighbor gave me his old truck last year, a 1995 C2500 5 spd 4x4 (build 10/94 in Canada) with a 350. It had been sitting for a number of years so he just towed it to my place and left it in the driveway. I managed to get it running last year and drove it to the back of the property as I had no plans for it at that time. Decided to dig it out of the snow yesterday and drive it to the shop, plowed 2 feet of snow off the hill and an hour later had it down to the shop. I found the problem with rough running in about 5 minutes. The ECM had some mouse schmutz on the connector so I removed and cleaned it all and it fired right up, CEL went out and it runs great now...gotta love EFI.

Anyway, the label has been damaged and is unreadable. Is there any way to tell what this ECM is, either by taking off the main cover and looking inside, or decoding the interior bar code number which is next to the EPROM? The EPROM is programmed with BDUY and the number on the bar code is 512159103484223. I can buy a 1227747 but if I don't have to spend $100 for an ECM, I'd rather use what I have.

I'm planning on using a 2.8L TBI unit which matches the demands of the flathead, and it's the same bore size.

Thanks for the help!

Cheers

Welcome to the forum!

Seems like you really lucked out with that deal. The four letter code on the EPROM is the key to identifying the ecm. BDUY was used in ECM number 16196396. It's listed as a 94 / 95 calibration for a 5.7L truck with 5 speed manual transmission which agrees with how the truck is built.

When its time to build the flathead it's best to use the expected horsepower or torque from the new engine to select parts for the fuel system. It sounds like you're already on that path by using the 2.8L throttle body. The 2.8 throttle body has significantly smaller bores but a low power engine does not need a large TB. You might save time by starting with a 2.8 calibration and ecm also. If it helps you could try selling off the unused project parts to cover the cost of the new ecm.

Good luck!

Cool! Thanks for the good news and info and thx for the welcome. :thumbsup:

I went to the wreckers today to find the 2.8 TBI but no luck...still have lots of other places to check. What I DID find there (yay) was a 1990 C1500 with the 1227747 ECM and it is all there, sensors, wiring etc. are still there. It has been converted to propane but it looks like the harness is all intact and it's at my friends wrecker so I should be able to get the whole system for beer. :happy: As my 1995 C2500 is a perfectly good running truck I would rather keep it as a farm truck.

On a completely different note, I pushed a 1994 Ford F-150 4x4 auto home with my Bobcat from another neighbor....all I needed was the brake pedal but he said I have to take the whole truck..oh well, I have 20 acres to fill. It has the MAF 302 in it and would probably work, but a little more work to use. I have already machined a Chevy points distributor to fit the flathead so machining a second one from the '95 will be snap.

It's supposed to snow major here overnight so work will be halted for a day or so....more later.

Cheers and thanks again!!

PS without doing a lot of research, can I ask.... is the primary "limp home" baseline programming in the EPROM or is it built into the ECM? i.e. do I really need to find a 1227747 that came in a 2.8L engine or can I program baseline programming and tune a 5.7L 1227747 ECM for use with the small TBI? thx... I'm still learning....thx for being patient. :scare:

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.

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!

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 painAttachment 17131

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

cheers

Quote:

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Originally Posted by 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!

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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.

Quote:

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Originally Posted by joegreen

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.

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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

Quote:

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Originally Posted by kilohertz

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

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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.

Quote:

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Originally Posted by joegreen

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.

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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

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