Odd Fire TBI

[dave w]

Agreed. Getting it to run is a good plateau to rest on. Fuel pressure at 12-13 psi is good. I'd aim for as much common ground between the two systems as possible. Do you have the info to change the number of cylinders to three? I can dig that up...

When I change the cylinder select value, Hex address 0016 changes. I think changing the Hex value to 03 would be the correct value?

See attached screen shot for an example of a 3 cylinder BPW (1.9 liters is half of a 3.8 liter V6 / figuring two 45 lb TBI injectors).

dave w

[1project2many]

knumcyl is a divisor and lower number of cylinders results in a higher value. Three cylinder is 96d or 60h.

[dave w]

knumcyl is a divisor and lower number of cylinders results in a higher value. Three cylinder is 96d or 60h.

Interesting; see attached.

dave w

[Willys43]

Well gents I have never been able to stabilize the secondary computor. I finally abandoned the spark control and put an HEI dist with mechanically advanced spark. Starts and runs, first time every time.

[dave w]

Thanks for the update.

dave w

[1project2many]

Interesting to note. Are you talking about the AFR? Or the spark timing?

[Six_Shooter]

Interesting to note. Are you talking about the AFR? Or the spark timing?

It's been a while since I read about the physical connections in this thread, but IIRC he was using one ECM for both spark and fuel and the second ECM for spark only. I can see how keeping the second ECM in sync would be an issue, especially where spark timing is so critical. fuel could literally be dumped in at pretty much any time, especially when it comes to TBI fueling and still run without a noticeable issue... *shrug*

[Six_Shooter]

Well gents I have never been able to stabilize the secondary computor. I finally abandoned the spark control and put an HEI dist with mechanically advanced spark. Starts and runs, first time every time.

Have you tried swapping ECMs from "main" to "secondary" and visa-versa to see if it's an ECM issue?