Howell - EBL/Timing Control ECU

[andybflo]

Hi All!

I'm in the process of installing a Howell EFI system on my '76. I reached out to Jim K for parts to add in timing controlled GM HEI (essentially the EBL computer and the wiring harness additions/changes.)

Wondering if these parts are still available? If not, I can curve/set my 4-pin HEI pretty close, but on the fly timing management is incredibly useful. Just picking the brain of the collective here to see if there's any guidance/advice, or if anybody has an alternative source for the ECU/Harness.

Thanks in advance-
-Andy

 

[LQQKatJon]

The ebl has been discontinued lately, but a guy is breathing life back into the availability.

Crossfire Injection Company Blog — Xfire Performance LLC

1982 and 1984 Crossfire injection company information page. Also information about crossfire Camaro, Firebird and Trans Am.

www.xfireperformance.com

I think you can still hook the howell up to a computer controlled distributor. You just dont get the tuning?? There are better experts. You can used get that with an affordable efi kit. But a quick google and is affordable efi now
Defunct too?

There also is ways to “burn” chips on the old ecu’s. But that is way beyond my knowledge of how to get that done.

Hopefully new ebl ecu’s will be available soon.

 

[andybflo]

The ebl has been discontinued lately, but a guy is breathing life back into the availability.

Crossfire Injection Company Blog — Xfire Performance LLC

1982 and 1984 Crossfire injection company information page. Also information about crossfire Camaro, Firebird and Trans Am.

www.xfireperformance.com

I think you can still hook the howell up to a computer controlled distributor. You just dont get the tuning?? There are better experts. You can used get that with an affordable efi kit. But a quick google and is affordable efi now
Defunct too?

There also is ways to “burn” chips on the old ecu’s. But that is way beyond my knowledge of how to get that done.

Hopefully new ebl ecu’s will be available soon.

Awesome on the EBL.

I do not believe that the Howell kit, standalone, can control timing. At least when I called Howell themselves, they didn't know anything about it (nor the kit in general, really, "the GMC guy" was not in the office.)

I do have a prom burner for GM style proms, but... I tend to believe that their decades of experience tuning it outweighs my knowledge on this setup. Give me a Holley EFI, and we can talk, but I wanted something where I could walk into a NAPA somewhere, and buy a sensor/part if needed. Hence, essentially, GM TBI.

I'm thinking Howell sells one a year, and it's just on the shelf until it's not anymore...

 

[LQQKatJon]

The ebl has been discontinued lately, but a guy is breathing life back into the availability.

Crossfire Injection Company Blog — Xfire Performance LLC

1982 and 1984 Crossfire injection company information page. Also information about crossfire Camaro, Firebird and Trans Am.

www.xfireperformance.com

I think you can still hook the howell up to a computer controlled distributor. You just dont get the tuning?? There are better experts. You can used get that with an affordable efi kit. But a quick google and is affordable efi now
Defunct too?

There also is ways to “burn” chips on the old ecu’s. But that is way beyond my knowledge of how to get that done.

Hopefully new ebl ecu’s will be available soon.

Did some more searching on affordable fuel injection…. Seems the company and guy is in trouble. Lots of bad news and he changed business name to advanced fuel injection andnkoved locations.

There is a facebook page dedicated to people who have been screwed. So probably not a good idea to get an efi system there anymore.

But they did have computer controlled distributor for their efi kits. So you should be able to do a computer controlled distributor with the howell ecu somehow.

 

[andybflo]

Did some more searching on affordable fuel injection…. Seems the company and guy is in trouble. Lots of bad news and he changed business name to advanced fuel injection andnkoved locations.

There is a facebook page dedicated to people who have been screwed. So probably not a good idea to get an efi system there anymore.

But they did have computer controlled distributor for their efi kits. So you should be able to do a computer controlled distributor with the howell ecu somehow.

Those are the vendors I use my AMEX with. If I don't get what I need, I file a dispute, and let the bank take the money back.

He's a bit of a force in the dunebuggy and boating community. We'll see if he can pull it off, and if I can get at least a pinout/map of the timing control harness. Then I'll consider wagering a few bucks on a EBL.

 

[tmsnyder]

I've been waiting for one of us to try this out:

Progression Ignition

Fully electronic timing control. Tuned with your smartphone or tablet. Wireless Bluetooth connection

progressionignition.com

Total control of your spark. No knock sensor but at least you could program your spark on the fly with your phone or Bluetooth device running the app.

If you wanted to use a knock sensor there is a system that JimK sells in which you set the timing advanced enough to ping, then the system retards the spark on a PER CYLINDER basis! Yes it detects which cylinder knocked and retards it proportional to the amplitude of the knock signal. After a certain number of cycles it adds the timing back until again it detects a knock, then repeats.

This way each cylinder is sparking exactly where it runs best.

 

[LQQKatJon]

Those are the vendors I use my AMEX with. If I don't get what I need, I file a dispute, and let the bank take the money back.

He's a bit of a force in the dunebuggy and boating community. We'll see if he can pull it off, and if I can get at least a pinout/map of the timing control harness. Then I'll consider wagering a few bucks on a EBL.

I will try to see if I have a printout of the harness diagram. There should be one on somewhere to download?

A gm tbi efi is all about the same. Howell, Affordable efi. Ebl.

I took a “painless” wiring harness. 60101 and made it work.

Swartzendruber EFI documents had pin outs for the ecu.

 

[LQQKatJon]

I will try to see if I have a printout of the harness diagram. There should be one on somewhere to download?

A gm tbi efi is all about the same. Howell, Affordable efi. Ebl.

I took a “painless” wiring harness. 60101 and made it work.

Swartzendruber EFI documents had pin outs for the ecu.

If you search. The original ebl website is on the “waybak machine”. You can see the wiring diagram there under the”information”. Flash II diagram.

 

[tmsnyder]

I will try to see if I have a printout of the harness diagram. There should be one on somewhere to download?

A gm tbi efi is all about the same. Howell, Affordable efi. Ebl.

I took a “painless” wiring harness. 60101 and made it work.

Swartzendruber EFI documents had pin outs for the ecu.

Jon what did you use for an ESC module?

 

[LQQKatJon]

Jon what did you use for an ESC module?

I was able to find a genuine gm esc for the 454 engine. I found the part number in one of the efi documents. I think part# 16131231

I am using that and the knock sensor in the water jacket.

My gm tbi/ebl system was done almost exactly as Randy’s write ups have it. With the exception of my wide band o2. I used a plx one that has bluetooth as well.

My efi has been Installed and running now since spring of 2019. I have not yet driven my gmc in 2026…. But I have started it up and it still fires right up.

 

[tmsnyder]

I will try to see if I have a printout of the harness diagram. There should be one on somewhere to download?

A gm tbi efi is all about the same. Howell, Affordable efi. Ebl.

I took a “painless” wiring harness. 60101 and made it work.

Swartzendruber EFI documents had pin outs for the ecu.

 

[RF_Burns]

Hi All!

I'm in the process of installing a Howell EFI system on my '76. I reached out to Jim K for parts to add in timing controlled GM HEI (essentially the EBL computer and the wiring harness additions/changes.)

Wondering if these parts are still available? If not, I can curve/set my 4-pin HEI pretty close, but on the fly timing management is incredibly useful. Just picking the brain of the collective here to see if there's any guidance/advice, or if anybody has an alternative source for the ECU/Harness.

Thanks in advance-
-Andy

Here is the GM 7747 ECM wiring diagram from Dynamic EFI (EBL), (same ECM as used by Howell).

Resource icon

Wiring diagrams for EBL based 7747 engine control module

Feb 24, 2025

Wiring diagrams for EBL based 7747 engine control module

• RF_Burns
• Fuel System & EFI

Howell's GM system did not include spark control (ESC), but you can wire a Howell ECM for ESC by following the wiring diagram for the distributor shown in the link above. Note you must remove a small circuit board on the White wire which Howell used for the TACH pickup. This board converted the 12 volt pulses from the TACH output to 5 volt pulses the ECM required.

NOTE: I am not sure what the spark table looked like in the Howell PROM. If you do some digging back in the GMCNet forum you should find others who did the conversion with the Howell ECM.

Randy Van Winkle may have some knowledge about the ESC table in the Howell ESC.


Here is a link to Richard Waters document on conversion to Howell EFI and I believe he had ESC added to it, but I don't know if Howell changed the PROM.

Resource icon

Howell EFI installation by Richard Waters

Jul 29, 2025

An excellent detailed document on installating a Howell EFI kit.

• RF_Burns
• Fuel System & EFI

There are more documents under Chassis>fuel injection in the Resources section of this site.

 

[tmsnyder]

Andy, I'm not sure what your plan is for the ESC. I wanted at least a knock indicator on my dash and Bruce mentioned this in a post one time. I bought the one compatible with MegaSquirt. I don't know if it will work with the GM ECM. The signal is similar, it pulls the signal to ground at the detection of knock. Maybe Bruce knows if it works the same as a GM ESC on a GM ECM.

I like that you can adjust the trigger level of the knock for your engine with a pot adjustment, and the price was reasonable.

Engine knock detection and indication for all vehicles

I would have preferred an ESC from a Chevy 454 but was unable to procure one.