I currently run a 160 degree thermostat and constantly get the CEL coolant temp below thermostat regulating temp, is there a periphery bit for disabling this check?

 

What's the actual code you're getting? (ie. P0xxx)

 

that would be a p0128

 

You might want to give Periphery 3 (FDA) bit 15 ("P0128 CT Below Reg") a try.

 

i had an outdated periphery table that didnt have that description, i just noticed its right there in there more recent table thanks for pointing me in the right direction

 

There is also the full boost vs coolant temp setting in the Turbo section of most ROMs. It is normally 85*C, change this to 65* and it will be a little closer.

 

will running with no thermostat make this happen too P0128?
i took mine off and just got the code after 200miles

 

I recommend sticking with the stock 180 deg F thermostat. There are quite a few functions in the ECU that will only operate "normally" when the engine temp is at least 170 F.

Actually, that is an incorrect definition from the first release of ECUFlash. I thought it had been removed from newer versions of ECUFlash.

 

On my 88580013 rom "min temp for full boost control" is still in there.
I believe it is realy "ALS Fuel Injection Time".

 

Yeah, its definitely not "min temp for full boost control".

 

I wonder, what those functions are in the ecu so I can seek them out in the tables and change them. As I'm sure you know, heat is the enemy so to speak in any engine. So I would like to manage this as best as possible.

 

-There is still some low temp timing trimming under 171. This is for catalytic converter heating purpose. It will kill MPG and you don't need that.
-Idle mode is over ~171F. So idle timing stability, ISCV trims doesn't adjust below 171F. I don't think this parameter is defined or tunable.
-Many ISCV demand% table are set with a much higher value below 171F.
-Some fuel tables (accel enrich) will make the car richer than necessary at 160F, making the tune go off when the engine temp gets over 160 (i.e. road racing/agressive street driving/hot weather).
-Thermofan is set for higher temperatures so you'd have to lower those settings to avoid the fan waiting until 190F to start.


It could be tunable for sure to get more consistency, but seriously a 170 degree thermostat would be a better choice, and a 180F one would be a MUCH better choice

 

I 2nd this. Your engine was designed to operate between 180F-200F. Running it out of this range could cause long-term premature wear, not to mention the engine is most efficient at higher temperatures (power, gas mileage). There is no reason to run such a low temperature thermostat.

 

Too much, or too little...that's where heat becomes the enemy.

Properly managed heat, that's where it's at.

 

100% correct