I've bought a TCFI IID recently and installed it on the bike. Now, aftersolving some ignition and idlelling issues, I'm trying to set everything else up, but in the manual I see a lot of times the expression "hot soak" andcan't understand the meaning... Of course I'm not native english speaker, so it will be helpful if someone could explain in more words what hot soak or hot soak start means...

Tnks a lot...

Hernan

 

Heat soak/hot soak: It is when, say, you ride your bike hard, then stop. The motor will actually get hotter as it sits there, not cooler. I've watched this happen with a cylinder head temp sensor on the fuel injected Sportster. Now you have a really hot motor and it will have different fuel requirements and behave differently than a cool or even just hot motor. When you go to start it up again, you have a hot soak start.

 

I got it, thanks Dr. Hess, but, the question now is, how can an EFI module, TCFI or OE, thru the temperature sensor, recognize if the engine is in "hot soak" or its just really hot??

 

Well, there could be numerous ways to do it programatically. For one thing, ECU's typically keep a "run time" variable. Like how long the motor has been running. If the motor just started and the CHT is 225F, you got some heat soak going on. But it doesn't really mattter if the motor is hot from heat soak or from sitting in traffic. Either way, you will have the same effect and the same conditions to fuel for.

And your English is much better than my Portuguese, which is primarily limited to Beer and French Fries.