IAC Steps - bin values

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midnightblue
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Posts: 6
Joined: Wed Dec 29, 2004 3:19 am
Location: Milton Keynes, UK

IAC Steps - bin values

Post by midnightblue »

I'm running MS-II on a v3.0 pcb and a GM stepper IAC

I have the bin values setup, however the correct stepper position in the top bin at 71C (160F) is fine when the engine is at that temperature. However as the engine heats up further, for example sitting in traffic, it needs even less air and therefore starts to idle faster and faster.

I think I need another bin at about 82C (180F) and another at about 93C (200F), but there doesn't seem any way to modify them.

Aside from that I can't see what the -40C (-40F) and -29C (-20F) are useful for. I'm not sure that you'd even start an engine with a coolant temperature that low, the oil would be very thick and the antifreeze solid! I'm sure there is probably a good reason for this, I would just like to know what it is!

Many thanks, Matt.
Lordprimate

Post by Lordprimate »

Hmmm why has no one stepped up to this Question...

I thought the same thing when I first started setting up my Table....

I mean how meny cars are at 40 below Zero when they start......
Lordprimate

Post by Lordprimate »

Is it possable?
midnightblue
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Posts: 6
Joined: Wed Dec 29, 2004 3:19 am
Location: Milton Keynes, UK

Post by midnightblue »

I'm still keen to find out what the logic is here.

I would imagine it's possible to start and run an engine with an AIR temperature of -40. However, the MS bases both its Idle Air and Warmup Enrichment on COOLANT temperature.

The values must have been chosen for a reason, or because of a standard way of calculation. I'd just like to know what thas is?

Many thanks, Matt.
89gtar
MegaSquirt Newbie
Posts: 2
Joined: Wed May 10, 2006 11:00 am

Re: IAC Steps - bin values

Post by 89gtar »

you can change the temperature values vs steps to represent what you want just highlight the temperature and hit backspace and then type in new temp
for instance mine is set at 190 degrees for the highest bin at 180 steps
3rd gen Transam with 355ci 6spd manual MS2 version3 2.89B&G
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