Who has idle issues with lights on or A/C on?
 

Well here's the deal.

Just like everyone who has a Microtech and no BAC, I have idle issues.

In order to maintain idle at an acceptable level with the lights on I have
to run an abnormally high idle. lets say 1100 rpms. (mild street port)

Once I turn on the lights it'll drop to 1000 rpms. If I needed the A/C too
thats where I hit 500 rpms.

Car wants to die once I push in the clutch at the stop and the whole thing
is unpleasant.

Now I can successfully tune the car with the A/C and lights ON. However,
once I turn everything back off the idle is way too high again.

So, I decided to try an experiment.

I am going to use the aux in to set up an increase in timing when the car
is at idle throttle and either the A/C or the headlights or both are on.

(Please note I am using the headlights as the trigger not the running lights.
For some reason the running lights do not drop my idle significantly.
My last rx7 with a microtech dropped idle with the running lights on.
but not the case in this car.)

I'll update the progress here so "stay tuned" my friends.

Joe

My car is a half bridgeport FD with no IAC. Using a PFC but concept should be the same. In order to run my AC, I increased timing in the cells that the car idles at with the AC on.

It didn't take long to do and works well for me.

Awesome!

It is great to know it is working for you because it lets me know I'm on the right track.
If it works for a half bridge it should work for most street cars. We're making progress here and it's exciting.

I should clarify that I have an LTX-8.
Unfortunately, that Microtech does not allow for changes to timing load cells when at idle.
You can only adjust timing at idle conditions. One setting for all load conditions.
You can however adjust the load cells for fueling.

Using timing for idle control is a great primarily because it's faster reacting then an IAC/BAC.

Everything is hooked up now.

Time for the test drive....

Stay Tuned.

Joe

Well the results...

It works so amazingly it's ridiculous.

I started with the A/C compressor relay and the headlight relay. turns out their right next to each other.

Using a diode I isolated them so they don't feed back to each other. I soldered their respective to a single wire.
[ on a diode there is a silver band. Think of this band as an arrow head for (+) current. The (+) current can flow in the direction of the arrow but is prohibited from flowing back]

Next, I ran the single wire into the vehicle.

Next, I hooked a micro switch up to the gas pedal. I adjusted the switch so that it is normally closed until the gas pedal is slightly pressed.

After that I wired in the relay so that it needs a ground signal from the micro switch and (+) 12vdc from the headlight or A/C relay.

once the relay has both idle pedal and headlight or A/C signal the relay feeds the 12vdc to the Microtech.

I set the Aux settings to add 15* of timing and 0 fuel increase.

I am very pleased with the results and drive-ability was so noticeable my wife even said that it was a nice job

First - I am not an Expert Tuna.

However, I would have some reservations with that setup the way I understand what you have done.

If you are running AC or your headlights, is your timing increased 15 degrees at all RPM and loads?

SO - the first time you turn on your headlights or AC under boost, the timing advances, and you explode? That sucks.

The Microtech doesn't have a Timing Map? :/

Whoa hold them horses!
 

NEGATIVE!

I think you missed the fact that I have a very precise micro switch placed on my gas pedal. and as soon as I touch the pedal and it comes off idle the circuit is cut and the aux input is returned to normal. Even under very very light throttle the circuit is not in use.

While driving the idle is only bumped up when the gas pedal is completely released.

Thanks.

Oh and it works flawlessly.

very very impressive i have the same issue.
so basically at idle with the AC on and the switch activated the microtech activates the Inptiming and adds 15 degrees of timing . you didnt play with the inpenrich or inpairadd feature at all?

do you have any pictures of the switch and how you mounted it ?

Yes Sir you are absolutely correct.
I only added the 15* and did not have to adjust the fuel or anything else.
I have a video of the idle and turning on and off the lights and A/C and both.

I'll go take pictures now and get them up for ya.

Well i took the pics but cannot upload them they must be too big

awesome mate !! pm sent :) if you have any pics or vids shoot them through via email ! save you the hassle of uploading

Done.
Email sent.

Hello,

Just a curious question, why didn't you just fix the BAC? Or get a new one or a working used one? I only ask because I have the same issue :-)

I have a FD engine in the car and no BAC. I an in the U.S. and Microtech has zero support here.
I would have to ship my Microtech back downunder and risk loosing it in customs.
Microtech would need to reprogram my ecu with the BAC feature.

So in order to take control of the situation I came up with this

Cheere

Oh ok cool! In your case I would probably do the same!
I forgot that on my setup I run both computers. My Microtech does the firing and fuel. The stock ecu does the rest