I know this gonna sound stupid but I had a thought.

Ok stock ECU idles rich, which causes the stock
idle to be rough.. Right??

So you get a reprogrammed ECU or Programmable
ECU and lean out the IDLE. To smooth it out. Fine..

This leads to my question:

So when you are sitting there say in traffic with with your leaned out idle to smooth out the idle. And as you sit in traffic the engine temps rises. Causing your Idle to be even more Lean.. Is this good or bad for your engine??

I realize the motor isn't under load from boost or what ever. but Just wondering if its good or bad for the car??
or would it be wise to just leave it a little rich to keep internal engine temps down????

Which leads to my next question..

OK your ecu leaned out idle, or you did with programmable to smooth yoru idle:
ok that being said - >

your Radiator fan kicks on, Thermostat opens to circulate the coolant thru the motor.. would it cool
engine faster if you bounced the throttle when the
fan kicks in?? to richen the idle gas mixture to bring down internal temps?? and Push fan cooled coolant thru
the engine block???

Am I making sense????

Lataz...

 

The ECU controls the injectors during idle, you have no control over how much is injected unless you have an aftermarket ECU. The mixture for idle is controlled by the Idle bleed screw located under the elbow. If you follow the proceedure in the manual for setting your idle, the mixture will be right and the idle speed will be correct. That is unless you have another problem or a vacuum leak. Do a search, I have paraphrased the procedure to make some sense.

 

I'm pretty sure that a rich idle=smooth but smelly idle. And a lean idle=a rough idle. I'm using an afc to tune some fuel out at idle without my airpump, and if I take too much fuel out it stumbles and stutters and so on.
My question is: why are you wanting to lean out your idle? If you have an airpump and your car is running properly, then the car should not be idling rich.

 

The car will compensate for an increase in intake heat so your mixture shouldn't have problems with respect to that. Not to mention higher temps will cause you to run richer if the mixture isn't changed, so either way it won't make you leaner. Nothing wrong with a lean idle, cars are generally tuned to run as lean as possible at idle once you're warm for emissions and mileage purposes, with the limiting factor being the idle starts to surge when it gets too lean. Other than that, the higher EGTs shouldn't be a big deal at idle.

 

Run your idle as rich or as lean as you want, running it leaner won't hurt it or cause it to run hot if your cooling system works properly. A smooth idle on a rotary is actually quite rich but too rich will make it not smooth and bounce a lot, too lean and it will want to stall (and may also bounce a little too).

Wade

 

the cats need a rich mixture at idle to operate. if you lean it out a little it wont pass smog, and if you lean it out more it won't idle very well.

mike

 

Thanks Guys...

I got a friend with a ECU programmed for
IC, DP, MP and CB..
He doesn't have IC or MP
And with the ECU richening the idle for the mods.
he don't have.. Would that make the Idle bounce??

Thanks