After running for 10 minutes or so, my coolant temp did not reach 200 °F. What could be wrong?

https://datazap.me/u/tequilaboy/doub...=2-24-30-33-36

Worried that I might wear out my cylinders. Please help.

 

Wear out your cylinders??????? Is this a serious post or a Diz post?

 

Ahh....looks like a 160 thermostat, with the fan on all the time, is what's "wrong". Cylinder wear is left over, tired out, beat to death LORE, from the old skool, IMO. Never seen it verified...only repeated endlessly.

 

high qwality hech too ooo. 160° t-stat is on the money. Also running pretty rich in double-fire mode with a negligible effect on coolant temp, but still cooling nonetheless. Sometimes a surge is just a surge even with a rich mixture. Go figure.

On a side note: The Detroit Lions found another spectacular way to lose today (yesterday now).

 

I think what IHBD was referring to was that at three points, the desired idle speed jumps from 800, to 2600....and the IAC reacts accordingly, going from ~20 to ~200....RPM follows. I doubt that has anything to do w/the A/F ratio....(?)

EDIT: Sorry, I don't follow the NHL.

 

Sorry, the desired idle speed increase is intentional and is triggered by the auto (A/C) button (C68).

I use this as a sort of primitive launch control feature which I refer to as idle launch assist or ILA. 4+3 car.

When the oil is hot, it will reach about 2,000 rpm with the desired idle speed of 2,600 rpm and 200 counts. Makes it easy to launch from 2,000 rpm and very easy to add extra rpm as desired with the throttle. This is also handy to use when topping off the coolant once the t-stat opens and the upper hose is filled causing the coolant level in the radiator to drop. The 2,600 rpm target and 200 count maximum are both exaggerated a bit in order to create more control error for a faster response and also to protect for possible IAC synchronization errors and help to ensure maximum flow.

I just happened to hit the auto (A/C) button and toggle back to econ a few times during warm up to force some IAC activity on this log, so that is what you see with the (3) desired idle speed jumps. The a/c status signals should also agree, but I didn't bother to look.

Fan activation at 90 °F is also intentional in an attempt to keep the intercooler temperature down and also to provide some extra load in order to increase the injector pw slightly and allow the car to run a bit leaner with the overkill injectors (63 lb/hr) in double-fire mode. Note: Fan will be deactivated 2 seconds after the car exceeds 11 mph, so it won't be running continuously while the car is in motion. Fear not, it will be activated again above 215 °F while in motion with the current tuning.

 

Just so I'm clear... Double fire mode is simply just batch fire... correct?

 

Double fire mode is batch fire, however the calculated pulse for each 4-stroke cycle is essentially cut in half and delivered each revolution instead of one big pulse per 4-stroke cycle as it would occur in single fire mode. Double fire mode is enabled by default in the 86-89 maf cars. Single fire mode is an available option that can be selected.

Due to injector pw limitations, linearity and latency issues at small pulse widths, single fire mode can run considerably leaner than double fire mode.

I go back and forth all the time, but usually end up being happier in double fire mode despite the rich mixture in some light load situations.

Some more detail regarding single fire and double fire modes can be found here: https://www.corvetteforum.com/forums...fire-mode.html

 

man that's some crazy tuning...lol

 

I love be able to learn about one of my favorite subjects! Thank you Gentlemen!