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Steve M wrote: How close to the sensor did you start your shielded cable?
Where did you ground the shielding?

On my Bosch distributor, there's a small rectangular two pin plug on the side for the sensor connection. The shielded cable starts right at the plug.
Only earth one end of the braid, just find a good earth point on the body somewhere. To be safe, don't use the same earth point that the ignition module or coil uses.

Coil disconnected (grey and black plugs) = no RPM signal (as expected)

I would have expected an RPM signal with the coil disconnected - unless as delco suggested you removed the power from the ignition module as well by unplugging the coil.
You could try just removing the HT lead, that would help rule out the plug leads and internal arcing inside the distributor if it stops the RPM issue.
And you might want to leave the fuel pump fuse out for all your testing until you get the RPM issue sorted. Every time the ECU sees the phantom RPM signal it's pouring enough fuel in to match.

I have now tried it after connecting the two coil positives together (pinks).

Distributor reluctor, no injectors, coil +'s connected = same RPM signal problem, but there is a signal.

I'm going to cut my reluctor wires as close as possible to the sensor and run some shielded microphone wire (2 core) from sensor to HEI module.
At least then I know that I've done what I can with that part of the story.

Festy. when you refer to coil earth. Should there be an earth other than the two original Camira plugs? The steel mounting bracket is bolted to the chassis, does it need something else?
I have the two standard Camira two-pin plugs connected to the coil.
I also have the car's original IG coil earth point screwed into the new coil mounting bracket. I don't think that should be a problem as it's a redundant earth lead screwed into a bracket that is mounted to the chassis.

Pull the 4 pin plug off the ignition module and just leave the coil and trigger wires connected. Pull the plugs so it cranks easy see if you get a good regular spark out of the coil lead to the head. It should just crank and have spark locked at 10 degrees and will take everything but the ignition system out of the equation

Looked at your log you have s problem with the map sensor it'd throwing a high map code and the key on barometer reading is pegged at max. You also have very low volts when cranking dipping to 8.5v at one point but generally under 10v the whole time while cranking and a few other weird things going on with spark advance. Can you read the tune off the nvram with ose flash tool and post it up here

Hi.
MAP
The engine has always run with very little vacuum due to the quad throttles and big cams. The lowest idle MAP I've had is about 60kpa. Would that set the MAP error?
When driving through hills it has had baro problems, leaning out badly until I go for high throttle/low revs for barometric update. I've tried a couple of MAP sensors, all the same.

I haven't used the flash tool before. Do you want the CAL or the whole BIN?

Whole bin then I can see if anything has got corrupted. I would probably turn the baro run update off unless you are going thousands of feet up and down in a short amount of time. Do you have all the itbs linked into a vacuum manifold then connected to the map

Throttles are mounted on factory carb manifold with balance tube. MAP vacuum hose comes from there and passes through a carb fuel filter acting as a vacuum reserviour.

I tried running the car without the baro update and it was almost undrivable as soon as I got up the first foot hill. I don't think it should be like that though.

I'll pull the bin for you.

Running the ECU in alpha-N mode might be a better bet here, ITBs just don't give good vac signal.

Hi Vlad,

I couldn't find any information for running in Alpha-N mode so I didn't pursue it.
If anyone has done it successfully with one of these ECMs I'd be keen to learn more than just clearing the load variable flag, which is all I know about it.