EFI Equipped Engines

As I am reading the the manual for the SESPRT, it is explaining how the ESPFI system is designed and how it functions. So far from what I have read it is saying that there are specific steps that the ECM is taking.

My question is this....Why do so many people say that there is no real need to allow an EFI bike to warm up?? This manual clearly states that the ECM refers to a "Look UP Table" and adjusts settings accordingly...My understanding of this is that the ECM is going through what those with a carb do, it is basically adjusting the AFR (Chock) to keep the bike running until proper engine temp is achieved..?????

it looks at the ect and keeps the motor in open loop till it gets proper temp then it will then go in to closed loop operation. its about a 3 min or so if you look at data from a cold start you will see a desired af value and cold start counter . it will go from 11.7 at start up till its warm and see the desired af continue to change till it gets to 13.7 to 14.0 depending on the map installed and iac counts start to drop aswell as idle speed.

So basically you are saying that it is better to let the bike sit for those three minutes instead of starting it and taking off right away????

It also depends on the oil your using! Dyno or Syn?

Not so sure that I buy that claim...

Just joshing, trying to hyjack ya. :roflmao:

:gah::gah::roflmao::roflmao: You're not that good at hijacking threads though..:roflmao::roflmao:

Oh yeah! I did it pretty good on the "Taken to the Beach one!" of course CB helped a lot. :roflmao:

Too bad there is no middle finger icon!!!! If there were, I would be flying it at you right now!!!:rant::rant::roflmao::roflmao::hijacked::hijacked::rant::rant:

:hijacked: :roflmao::roflmao::roflmao:

that is funny right there!!

OK, I'm outta here. Sorry. Thanks for putting up with this bored, stir crazed horny old fart. See ya.

Back to the question. Baggerpaul is correct with his running description of a cold start. The factory sets the air/fuel ratio @14.7 to 1 according to EPA mandate. That is why everyone says they run hot (too lean). Unfortunately, you cannot adjust this unless you have a fuel injection tuner (SERT, ThunderMax, FuelPak, etc.) that reads and adjusts the map to a lower ratio. This happens thousands of times a second.

The ECM also reads oxygen level and barometric pressure to keep the motor running clean whether cold or hot. You'd have to have one hand on the carb choke constantly while riding the first few miles to achieve this, and you still could not match the speed or accuracy of the ECM adjustments.

As with anything starting-up from cold, common sense tells you that you can't drive away quickly because the OIL has not circulated enough to give good mechanical protection. Computer doesn't care about the oil, it just sez "wake-up let's go!"

My understanding is that when you hammer on a cold engine it puts a lot of stress on the head and base gaskets. That's was one of the reasons earlier bikes had seeping base gaskets. Gasket materials are always evolving and are pretty tough today but still it just doesn't seem smart to hammer on a cold engine.

I usually start up and drive away slowly in the morning just to get out of the neighborhood, but if I could I would let it sit and idle for 5 minutes.

Yep, you are absolutely right on this. My point is that just because you have the ECM, it shouldn't mean that they should not let the bike warm up. This is why the ECM has the multiple look up tables, it is for transitions. IMO Basic same concept as the chock only in the chocks case, it is done manually and not as accurate..

Not only that, the oil hasn't come up in temp. That can cause so issues. JMO

I wouldn't be beating on a cold motor ever. The Evos would leak from the base gaskets if the motor was run hard before it warmed up. With the cylinders held in place by the studs that were screwed into the crancase and then clamped down by the heads being bolted to the studs the gaskets were clamped better by the alumimum expanding as the motor warmed up. The old rule of thumb was to let the top of the rocker boxes get warm before you ride off..it worked well for me.

I think that this is just as important with EFI engines just as it is with carbed ones.. Great Point Sleepy..

I always wait until my oil temp is at about 100* before I take off. Of course I when it gets colder here then I get a little impatient.