Rover V8's, EFI and aftermarket ECU

[EggsBenedict]

I've had a Rover V8 in a number of cars that I've owned over the years and reading through threads on stepper motors, air bleed valves, shunting etc. and the blame being laid at the EFI set up (mostly) leads me to question what it is about the EFI that needs all this stuff? I had a Triumph Stag with a Rover V8 in it. Had a horrible bonnet bulge to accommodate the twin SU carbs it had. I swapped this set up for a Holley 390 on an Offenhauser manifold and slimline filter and that sorted that.

Point of this story is that with the old SUs and the later Holley, there was no idle control valve or stepper motor, no shunting, not any of this stuff - just smooth running V8. Not massively powerful (it was dyno'd at 160 crank) for a 3.5 litre motor, but it ran really nicely. So why is that stuff there? You would have thought that will all the modern tech that goes into an ECU, you could map up an EFI that didn't need the 'workaround' of a IACV?

There is another slant to the question - if I fit my Emerald ECU that I have waiting with the crank sensor, coil packs etc., can I just whip off all this junk (stepper motor, hot wire sensor etc.) and just use the ignition timing idle control, air temp sensor and throttle pot and expect the idle to be OK?

[Pupp]

Loads just use the idle ign advance table with no IACV... I just liked the fact the IACV gave a bit more flexibility for cold starts/ running etc. The two wire PWM Bosch type (typically Vauxhall or Saab) work well and are easy to configure so no reason not to.

[blitzracing]

Simple reason, the EFI gives both more power and better economy than carbs when set up correctly. It all went horribly wrong when you try and force a 40 year old engine design to run in emission compliant mode with catalysts, so its not a fault of the ECU, Lucas just did the best they could given the new emission laws. The shunting is more due to using a plenum intake system combined with a high performance cam not making good bed partners.