Dynotech Tuning

iTrader: (12)

So almost ALL evo's I have dealt with have some sort of ISC system still in effect. Lately, we've had a few come in that are running an Infinity Q45 throttlebody with no ISC system at all. I started looking at all of the tables that will still be useful and which will need attention.

If you intend to still use the 'Idle Stability Timing Control', I assume the 'Target Idle RPM' tables would need to mimic what the engine will naturally be at idle, otherwise the ECU has no idea which RPM it will try to target as it adjusts the ignition timing to stabilize the idle RPM. Otherwise, it may be best to set the stability timing control to zero.

The biggest issue I have noticed is the cold start RPM since there is no additional airflow being added to raise idle until the engine warms up. I also noticed that the decel fuel cut won't engage as soon as I would like,when the vehicle is driving, so it doesn't surge as it returns to idle RPM as the fuel injectors are triggered on/off.

If anyone has any tips on any tables to disable or focus on, I would appreciate the conversation.

-Jamie
(aka Jack_of_Trades)

gear head

iTrader: (3)

I have been running without an ISCV for about a year now. If I remember right I had to make adjustments to the MAF comp vs. coolant temp, timing stability, cold start timing map..there may be one or two more that I'm forgetting & I'd have to look in my ROM to see exactly how much I changed the values.

Upon a dead cold start up I generally have to hold the throttle at 1500 RPM for about 30-45 seconds then it idles on its own. I'm sure If I played around with it alittle more I could get a better cold start but I'm fine with it for now.

Dynotech Tuning

iTrader: (12)

Thanks for the reply. We actually just took all of the measurements of a 1G DSM, 2G DSM and Evo 8/9 throttlebody and sent everything over to our machine shop so we can start offering ISC blocks with a built-in BISS screw so people with these type of throttlebodies can still have idle control with their original Idle Control Valve.

If anyone is interested in this, PM me.

-Jamie
(aka_Jack_of_Trades)

Spec-Ops1

iTrader: (38)

I would like to see the final results with this Jamie...

Dynotech Tuning

iTrader: (12)

So I am going to try a simple add-on to possibly help with cold starts and increased idle RPM. We have a box of about 20 stock evo boost solenoids so I set the IC Sprayer parameters to control that solenoid in a on/off state. Once coolant temps reach an acceptable temp to retain the preset idle, the solenoid will close and blockoff the air bypass. This can be tailored pretty easily with a boost pill too. Its worth a shot and can be very inexpensive.

We'll see.

-Jamie