MoTeC Global Forum

I am running an M800 based on TPS/MAP with a 1993 Ford 5.0L windsor small block. It is more or less a daily driver so am trying to setup the ISC Ford part # E9AZ9F715AA for cold starts without much luck. It operates at 160 Hz square wave & zero signal is minimum duty cycle. I am told duty cycle can be anywhere from 20% to 80% but realistically between 40% to 60%.
Has anyone done any work on this type of setup. Seem to be too lean at start then cant get enough fuel in then it turns too rich. Needing to use external Lambda sensor as the 2 we are using as inputs to M800 still havent heated up in time to start reading. By the time they do engine is already warming up - so we miss the cold start.
Any ideas?

Richie.

I haven't worked on that type of setup but I can give you some info regarding the lambda sensors heating up.

If you go to Adjust > Sensor Setup > Wideband Lambda Setup > Sensor Type and set both to Fast Heat the sensor will start to heat up as soon as the ECU is powered up, you will then be able to use them for setting your cold start/idle fuelling. Once you have finished doing this I would recommend setting them back to normal heat as the fastest mode increases the wear rate of the sensors.

I might be wrong, but isnt 160Hz too high for such a valvle?

The bosch Idle control valve (3 wire) works well at 20Hz.

Thanx for info on Fast Heat.

Yes the ISC is 160Hz & works well after engine warms up & works of the next part of table. It's just that on cold start first thing in morning we are letting in too much air & cant give enough fuel to keep up with air - it would drown. So then when we get the fuel in it turns rich & so on. I suppose it is trial & error. Trouble is you only get one shot at it eah day for about a minute.
Am just looking for a way around it - other than remove ISC altogether.

Richie.

Hi Richie,

I use the same valve on my engine with great success, Is it only a problem at idle? or lean everywhere? How well setup is your engine temp compensation? I can look at your cal file if you want and see if I can find anything.

Cheers
Aaron

Aaron,
see PM - can't seem toget attachment to you.

Richie