My tickover is very unstable when cold (below 25 C) and I have to keep her going with a light touch on the throttle until things warm up. This is a right pain when reversing out of my garage and turning round.

I am running Easymap with an MBE ecu.
As I am not running an idle control valve, what can I do to improve this?

I've tried increasing the values in the lower temp sites of the Ignition_Coolant Temp at Idle Map (added 10 degrees up to where it tapers off) but no real improvement.
Any ideas will be appreciated as always


[Edited on 24-4-07 by RazMan]

by know means an expert are you running any warmup enrichments ( from a fueling piont of view )?


regards

Agriv8

Only the usual fuel / coolant temp compensation. I have tried increasing the fuel at low temps but it doesn't seem to make much differerence. I would have preferred to have used the idle control valve but apparently it is rather tricky to put into the map.

Cold idle is such a pain to set up as you only get a couple of goes before the engine warms up.

Having a notch in the spark map is a technique used to stiffen up the tickover. It adds a small amount of advance if the revs drop.

Colin

I have a feeling that the ignition advances a little (among other things) if the revs drop below 500 rpm or so - a sort of default mode. It does this when warm but doesn't recover enough when cold. It just means I have to annoy the neighbors until it warms up.

I have used the 'notch' before and it works.
Assuming you are using speed v throttle
You can put speed break points at say 500, 750, 1000 and at the lowest throttle break point put for example 15, 12, 15 deg spark and the engine should naturally idle at 750rpm.
You can smooth this out to the next throttle break point to ensure it always sees this dip in ignition.

Good luck.

Using an Idle valve shouldn't affect your Map.

Opening the valve will allow more air in (obviously!!) which will affect the manifold vacuum, so the speed/density algorithm should automatically adjust the fuelling as if you opened the throttle slightly.

According to my mapping guru, my ecu has issues with idle control valves. I am not 100% sure he just couldn't be bothered to put the time in.

I think I will have a go at 'notching' the idle very slightly and see how it goes, although I don't want to mess up the very stable warm tickover and worst case scenario is only warming up the engine before moving off.

If your fuel map is based on throttle position (alpha-n) then an air bleed valve will confuse the ecu. If you use manifold pressure then a bleed valve should be indistinguishable from just cracking the throttle open slightly.

That's probably why my mapping guy said that it wasn't easy to install the bleed valve - it doesn't have a manifold sensor afaik - just a tps.

[Edited on 25-4-07 by RazMan]

any chance you can fit (over simplified) a button that increases the tickover to 1200rpm when pressed?

Aha, lateral thinking - I like it.

I seem to have conquered the problem for now. I put in about 10% more retard when the coolant was below 20degC and it seems to have stabilised quite a bit but only time will tell.