Relooking at warm-up

great work.................................. looking forward to your observations

 

As long as you don't assume this coolant temp beeing 40C.

In actual fact, "Request Warm-up" can return "1" and the car be in the midlle of an S1 at 70C, as i measured yearstday in Torque, just because you stopped the car for a while, even if the engine is warm well above 40C.
So i guess the catalyst temp has something to do anyway...

 

Bob, testing today with Torque an S1 made entirely in motion, and with some slight acceleration in it, i found an upredicted behaviour that could be relevant to the discussion.

If you look at the area markd as "???" you'll find, in the middle of S1a, an abrupt inversion of Timing advance and a relative fall in the current from the battery. Unfortunately the 1 sec delay time of the data collection does'nt make it very clear, but i see a definite pattern of ICE collaboration.
What will happen if the acceleration was the flooring as mentioned in this thread?

I think this is interesting beyond the scope of the thread, cause potentially can make you confident that you can make it out of steep ramps, even in S1a....

Speed in km/h ; current in Amp ; SOC in %, Timing in Deg.



Comments appreciated.

 

Great data! The other day I tried flooring it while in S1a to see if I could get the car to leave S1a. Even with the power demand filling the PWR area on the display the ICE timing stayed negative and under a low load. The HVB provided all the power, showing about 125 amps of discharge to accelerate during that time. I only held my foot down for 1-2 seconds because I was on a residential street and didn't want to damage the HVB discharging so rapidly.

When I performed this test the car was relatively warm from running errands, but just cool enough to require S1a upon starting.

 

so at this point the question remains
so what can we hack to outwit the sensors[and toyota engineers]

 

Can I see this same catalyst temp data on the ScanGauge?

 

will be really useful for those who stop/start motoring a lot or short journeys...to improve mpg

 

Interesting thread here even just scanning through the posts quickly... i'll have to read it again 2 or 3 times to digest it thoroughly..


Just my .002 gal worth, the only way to skip S1a is to use an engine block heater so that coolant temp will reach above 50C (in warm climate) so one can drive off right away in S2. In cold weather, the highest I saw was about 45C and i think it just took me to S1b. But still, S2 wasn't far away.

This will decrease the amount of fuel burned, but will increase your power bill a bit depending on the cost of electricity.

 

even with engine block heater the CAT has to warm up....which is part of s1a ibelieve...but it is quicker and cost of electricity is cheaper than petrol burned

fooling the CAT is the way to go.....not good for emmisions...but burn less fuel[more green??]

maybe..maybe not????

 

haven't really experienced S1a-like behavior in the ICE when coming from a 50C coolant start up using the EBH. S2-S4 is just like the normal S2-S4 behavior if coming from a cold start. O2 sensors might be warming up but already giving correct signals based on coolant temp as interpreted by the ECU (?)

 

suppose what i mean is the engine will come ON even with the temp 50C

so with stop/start driving....as i do deliveries.......this initial start up comes even at 60C IF IT BEING LEFT long enough
so the CAT must be cooling a lot[mmm...idea for insulation on some of them pipes underneath!!]

 

I don't think the CAT is cooling that quickly. In the morning after <5 min drive I stop at kindergarten, the engine completes it's warm up and is off. I normally leave the car in ready state, because if I turn it off I'm facing another warm up cycle (it is shorter, but still), but if I leave the car for <5 min in ready state, it doesn't go into warm up.

 

i did'nt mention how long i stopped for>>>>>>.
could be 15-20 mins

but as you yourself say if you turn it off ..it WILL have another warm up cycle

anyway....why? does it go into warm up cycle even if stopped short time and engine is still 60C or so
is it the CAT that needs it or the engine?...or does it just do it

[does the car doors lock in ready mode...never tried it myself...could be useful on some of my stops..to stop warm up cycle]]

 

No you can't lock the car in ready mode, when the engine is warm enough (80-90 C) it won't do another warm up, but winter slow city driving the engine coolant is below 60 C.

 

so back to where we started!
so it's the CAT making most of the demands
since even on cold morning ..once it reaches 40C initially engine will shut
but later even if engines has cooled to 50 - 60C from 80-90C.....engine will start a cycle ... so something is requesting it!

i don't have the gadgets to check these .....so maybe bob or someone has

might be helpful in knowing why stop/start gives such an mpg hit!

 

it could well possibly be.. however, i haven't experienced this phenomenon before where the ICE will do another warm-up cycle when the coolant temp falls to around 50C. perhaps your SOC was low at those times to warrant a charge cycle not a warm-up cycle?

 

Could it be because the pressure on the pedal did'nt lasted enough time? For this particular situation i guess one have also to take in account the SOC: mine was at a rather poor 48%, it could be possible that before let ICE breaking in, the max output form the battery is taken in account.