Right,

So I have all the inputs configured to my VEMS ECU ( its a variation of the Megasquirt - even uses megatune )

See



meagatune Vems SCr Shot

So

Question 1

VEMS ECU can controll the idle control stepper motor do I need this ? ( I have a spare unit under the bench )

Question 2

If i dont idle use the idle control valve question 1 I assume that I to set the throtle butterfly slightly open but what controls the tickover ?

Question 3

The ECU was bought setup to run on batch injection ( I.E. L and R injectors fire together ) I can set this up to sequential fire is it worth it ? How will I work out if these are upto the job formula somewhere.

Thats it for know ( I am sure there will more later ) many thanks Agriv8

Oh best give some background info

Rover v8, 4.2 Vems driving Fuel and spark.
Act performance plenum, Ford throtle body. high lift cam.

You can probably get away without the idle control if your prepared for a bit of footwork during warm up.

Putting a V in the spark map around tickover is a good approach as it holds the tickover a bit tighter.

I made provision for the Ford PWM idle control but never got round to fitting it.

I am not using sequential injection either.

HTH

Cheers,

Colin

1. You don't *need* it, but it's usually a nice thing to have. I've run without idle air control before, engine can be a bit difficult on cold mornings but you can work around it, and it'll be fine as soon as it's warmed up. I'd leave it for now, you can always put it on later.

2. Idle speed is controlled by the position of the throttle butterfly and/or an idle air bypass in the throttle body. You can also use the ignition advance angle to keep the idle rpm steady (increase the advance just below idle rpm and decrease advance just above it). You won't have any facility for extra air on a cold start (sort of like a choke), so you'd have to hold the throttle open for a few seconds to keep it running but it's no biggy.

3. I wouldn't, certainly not if you're just starting out down the EFI road. Batch firing is perfectly adequate for our kind of uses, and it'll be far easier to get it running well than it would with sequential.