It's not bad.

Some of the diagnostic tests call for running the motor with the jumper in place to observe the car going into closed loop. I think the flashing slows down when it reaches closed loop.

 

Yeah mate that was the only possible argument i could see for the warm engine too. I cant see the difference being all that large in terms of screw position between hot and cold.
As Coaster says there is nothing bad about starting with the A & B jumped, id say the reason it is stated most of the time to turn the key on but NOT to start the engine is probably due to the results and function youre after.

 

True, when under control of the ECM there is a "target" RPM for temp., likewise there is a desired IAC vs rpm etc. that is also programmable. The idle setting in the ECM will not change.
However, with the motor being *cold (see below) it may require the T. blade to be opened more to sustain, or to idle @450, as opposed to a motor already being warmed up at least. Then with the IAC plugged in, and under ECM control, because the min. air screw being turned in possibly too much to compensate the cold motor, it would then be possible to be out of range for the ECM to adjust.
The IAC does have a decent amount of "range" that it can compensate when under computer control and really only needs to get close. Obviously this would all then depend on: how cold is cold, and how much someone was twisting the screw to get it to idle @450rpm. I guess cold is relevant to where you live and a given day.
My Idea of a *cold setting, would be trying to set the min. air when the coolant/ambient temps. would be 50ish. Fahrenheit. Personally I have never tried to set set it up cold. I do it so I know where the counts are at O.T. If you are getting good results doing it that way, the result is all that matters.

 

It is not BAD to start the engine with terminals "A" and "B" jumped together. With the terminals jumped and the engine running, the ECM is in the "field service mode". But why would one consider using the field service mode for setting the minimum air adjustment, when it isn't called for in the instructions? Has someone discovered some undocumented benefit of setting the minimum air while in the field service mode?

RACE ON!!!

 

Ive just tried to reset the idle on my 1987 after fitting a new IAC valve. I followed the procedure as above, and when i connected things back up, the car was idling at 1400 rpm! So i just turned the screw down again, which defies the point of resetting it to the book really. Should i have left it at 1400 rpm and taken it for a drive to let it "settle"?

 

Yeah see this is where i couldnt see a point to it, now you mension 50*F i can see how it could be abit of a change. That is 10*C which is bloody cold and although im not in Western Australia, i know it doesnt get that cold here during the day here where i am on the east coast!! (its still winter here and we are getting around 70-75*F easy where i am on a cold day)
Thats interesting!! Did you adjust or check the TPS? Im not too familiar with replacing the IAC in an earlier car, but do you have to set the new one to a certain length before putting it in?? Was the tip shape identical to the old one it replaced?

 

YES. Or reaclimate it as outlined in your FSM. You don't just "reset the idle". The idle speed is burned into your prom. The proceedure above is for setting the minimum air adjustment. Did "i just turned the screw down again" reduce the idle speed? It shouldn't have. Turning the screw down (in) could increase the idle speed, but not lower it.

RACE ON!!!

 

I think he means turn it out as in close the blades.

 

I would have thought so too, but that isn't what he said. Besides backing off of the minimum air adjustment screw, shouldn't lower the idle speed with the IAC wide open. "You don't just "reset the idle". The idle speed is burned into your prom."

RACE ON!!!

 

Yeah mate thats right and , something else is not done right there.

 

OMG, this just makes me wonder if anyone bothers to read ALL of the posts...................

 

"7. Start the engine and adjust the minimum air to the specified (desired) rpm."

550 is the right RPM? I went out and tried this on mine just now. My car idles fine, 600 RPM in drive. I turned the screw as far as it would go and it would not go under 1200 RPM. Odd.

 

Me too. You DO realize what you quoted me as saying in post# 27, was in response to cymro's post# 25. You DID read ALL the posts, right?

RACE ON!!!

 

OF Course........

 

...but I do understand more and more of what's being said...