Chevy Cavalier to Toyota Yaris
 

Howdy folks,

It's been a while since I last posted but real life has kept it's ugly head in view but hopefully it's settling down some.

Perhaps the most important thing that's happened since my last post is that my car, a 1997 Chevy Cav, was t-boned by a Ford Crown Vic and totaled. It was/is still drivable but only because the local WalMart had a good supply of gorilla tape on hand to seal the damage and holes in the passenger side.

With the aid of the State of Texas and an AirCheck Texas voucher, I was able to purchase a new '09 Toyota Yaris 2-door 1.5L 4Cyl. 5-Spd. It had 7 miles on the Odo so it's a fresh start for me.

I've got a couple of questions though...

When setting up my ScanGuageII for the '09 Yaris, I set the engine size and fuel tank size and that went ok. When I went back to the instant readings on the guages, tps (throttle position) read 16 at idle rather than 0. I know my foot wasn't on the pedal so is there any reason why this would show incorrectly? Is there a way to check the throttle position on my own or do I have to take it to a mechanic?

Also, does anyone else here have a Yaris? If so, does anyone have tips for the little thing?

Driving from the dealer to work on the highway with the a/c on showed approx. 50-53mpg at 60-65mph. I know the ScanGuageII will have to be calibrated with a few fillups but does that sound about right for the car? The window sticker shows approx 32-36mpg for the highway.

Thanks and drive safe,

Jeff

97Cavelier -

(Sorry about the accident but glad to see you are back)

I think that's an artifact of the Yaris' drive-by-wire throttle. In that case, the ECU/PCM may be defining it's own value for the throttle. If you think about it, 16 might mean maintain "idle RPM". Google google google, more on the subject ...

Drive by wire system is [uncool] - Toyota Yaris Forums - Ultimate Yaris Enthusiast Site

CarloSW2

I have a Yaris! It's the 3 door with the 5 speed manual. When I drive between Baltimore and Washington D.C. I usually get between 46 and 52 mpg (it's mostly down hill). My best tank was 47.6, but winter has been hurting.

With the tires pumped to near the sidewall max the Yaris can coast real good--even in gear. And the injectors shut off while in gear with your foot off the go pedal.

Here is trick that someone at Yaris World found:Hang Time: Exploiting ECU Fuel Maps for Fuel Efficiency - Toyota Yaris Forums - Ultimate Yaris Enthusiast Site

My fuel log!
http://ecomodder.com/forum/fe-graphs/graph548.gif

Thanks :)
 

Thanks for the info so far. :) It makes for good reading while at work. I've also been reading on the yarisworld.com site and I'll be making lots of use of google for this.

Thanks,

Jeff

FYI, the throttle position sensor on my Firefly (Metro) does the same thing, except I think its idling value is 13.

Congrats on the new vehicle. Thumbs up.

In order for the car to idle, the throttle plate must be at least partially open, so basically the TPS will never read 0.

Hi,

The minimum TPS on my xA is 12.

What are the engine RPMs at 60mph in 5th? Or, how fast are you going at 2,000RPM in 5th?

In my 08 Yaris 2000 rpm in 5th is at about 45 mph. I think 60 mph is a little over 2500 rpm. I don't know if it is any different in the 09s.

Wow, lots of replies to answer this morning :) Sweet...

The reason I was puzzled with the TPS reading is that in my 97 Cavalier (2.2L 4Cyl - 4Spd auto) the TPS would read 0 when I coasted, either in gear or in neutral. I'd kinda figured that 0 wasn't the true reading since the throttle would have to be open to allow fuel to flow and keep it running but seeing the reading of 16 just surprised me. Thank you for the info :)

As for the RPMs that I'm getting while driving, I don't have my ScanGuageII mounted yet. It's just wrapped around the steering column and lays wherever I can stuff it while I'm driving. From the times that I have looked at it though, at approx. 60mph in 5th I think the RPMs are between 2500 and 2700 but I'm not sure. I'll pay more attention on the way home from work tonight.

Also, I noticed this morning that when I'm cruising at 45mph or below and take my foot off the gas and coast while in gear, the MPG readout goes to 9999MPG after approx. 4 seconds. I only saw this reading in my Cavalier when I'd kill the engine and coast to a light or coast down a freeway ramp. So... does this mean that the engine is actually turning off during coasting? It doesn't feel like the engine shuts off because I still have excellent steering/braking control and none of the dash lights come on like they do when I get into the car in the morning.

As far as I know my Yaris doesn't have any special features like that but the engine is VVT-i so I'll do some reading on that today.

And that is all the time I have for the moment.

Thanks again to everyone that replied, I do appreciate it.

Drive safe,

Jeff

The engine is still moving (because its directly coupled to the tires with the clutch out), but no fuel is being injected. This is called deceleration fuel cutoff. It is better to coast in neutral with the engine on if you are not going to come to a complete stop.