? about engine temps and ultra gauge
 

I finally got the Ultra Gauge, I like it a lot and I think my foot is much lighter now that I am seeing the instant gas mileage. I might average a mile or so more per gallon.
I have 2 questions:

1. My engine temps go to 204, when cruising at 50 around 18% engine load and outside temp of less than 40. It quickly drops to upper 190's when I give gas. Today it even went to 205, while I was waiting for a red light and the outside temp was about 33 degree F. after moving it drops to upper 190's and 201. Is that much rise in temp, when idling or cruising at constant speed normal?

2. The closed loop and open loop icon in the right upper, was open when I first started the car, than it closed after a little driving and I noticed that it will go to open, when I take my foot of the gas and let the Disco cruise. Can some body explain this to me, what it means?
Thanks

Open loop is when the fuel injectors are fully open and dumping in as much fuel as possible, think of it as full choke.
It will be this way everytime you start the engine, it stays open loop longer the colder the engine is, I will not drive while cold and in open loop.
Most fuel injected engines go into open loop when you take your foot off the gas, if you read the instructions on the UG web site they explain way, but I forget and I'm not doing your homework, sorry. ;)
That gives you more incentive to keep a constant speed doesn't it?
I even use my cruise control in the city, mile long stretch of road? Cruise!!

Yes it is normal for your engine temps to climb like that, especially with the smaller DII radiator.
And yes your engine temps are fine.

It will also go open loop when you floor it, max gas for the demand, as will a scanner. You may also want to check your fan clutch for operation, but like Spike says your temps are not out of reason.

My practice has been to start driving the car, when the RPM drops, I will see if it will ever go into close mode before starting to drive it

Fair enough, I read it, this is why I knew about the open and closed loop, but was probably not paying enough attention. But your explanation adds some simplicity to it, thanks. The manual says, that the mixture will be too rich or to lean, so I guess taking my foot of the accelarator, makes it too lean, correct me if wrong.

Other than gas mileage and engine temp, which gauges are important to keep an eye on?
I couldn't find fuel pressure and battery voltage, I asume they are not supported in D2.

IIRC when you first start your engine, O2 sensors needed to be pre -heated for them to work right. That's why the open loop at first ( no feed back between pre-cat O2 and ECU ). On hard acceleration, your engine goes to open loop coz it needs to run richer. Once the engine is cruizing along, it should be at closed loop with the ECU modulating the injectors to run between slightly rich to slightly lean by way of feedback from the pre-cat O2 sensor.

If for some reason one of your O2 sensors don't work right, you ECU may go into an open
loop.

BTW you can program your UG so you can see the voltages from your pre-cat O2.
I have my display set so the Eng temp and ave MPG at the top, left and right pre-cat O2
(bank 1, sensor 1 and bank 2 sensor 1 ) on the bottom. You'll see the your O2 sensors
at work.

Ed

Thanks Ed for your reply, I just don't know what I will do with the voltage numbers, not knowing what they are suppose to be. BTW I am going to Rave's now to see if I can find something

O2 readouts are in voltages. Voltage on a working O2 sensor fluctuate from .1 to .9
if your engine is running lean ( surplus O2 in the exhaust ) your voltage will be low and
visa versa.

It fluctuates that way to help the catalyst burn off the excess hydrocarbons and excess fuel by providing extra O2.

If you voltage doesn't fluctuate much expect an engine code soon.

Ed

http://www.autodiagnosticsandpublish...or-testing.htm

BTW there are 7 pages available so you definitely have lots of permutations possible.
Couldn't find oil pressure though. Still playing with mine, only 1 week old.

Thanks for your explanation and the link, good reading

For the most part, closed loop happens when the engine reaches a specific temp, at the same time the 02 sensor heaters are also working so as to improve emissions during the open loop cycle.
I do not believe the ECU goes out of closed loop when you speed up, open loop also means the ECU is no longer taking and processing information from all the other sensors and will not unless in closed loop.