Engin's running too cold?

[dom14]

I did a good 25 minute drive just before. Temperature still sits at the lower end of the dial reading.
But, I have no trouble heating up the inside of the vehicle via the heater.
I'll have to see how it goes.
Overall, it takes bit longer for the engine to get into the healthy coolant temperature by the looks of it.
I reckon, even in Melbourne cold winder, 10 minutes of driving should be enough for the engine to get to the
healthy temperature, provided the thermostat is doing it's job & the gauge is not faulty.

[dom14]

Regardless of outside temperature, the thermostat should not open until the engine is up to temperature. Exactly the same thing happened to my TB45, the first thing I noticed was that on long downhill runs the engine would get slightly colder, changed the thermostat and all good.

Exactly! That's what I experienced yesterday. I'll replace the thermostat anyway.

[Throbbinhood]

I dunno, I get the theory of thermostat keeping it that way..But my rig did the same with an old and a new thermostat. Going on a long downhill run it'd cool down a bit. My old Hilux did the same. They'd do the same if I just left them idling for ages, they'd just keep cooling down slowly. I don't know if once open, they don't close fully until a certain point or what, but it hasn't worried me.

What I have noticed now is that the auto choke (which I've had issues with previously, but thought i'd adjusted it enough to sort it) I believe is coming back on after a drive in cold weather, as it idles high for a bit when I come back to a standstill until the carby seemingly warms up a bit again and the idle lowers. Might wind the auto choke off a bit further.

[threedogs]

Having just fitted an extra water temp gauge, I can tell you
the after market gauge and the Ecu-Talk are pretty even
BUT when the OE dial shows the motor at running temp it is in fact
only 60-70 degrees on the gauges, well below my 85-88 operating temp
Hope that made sense lol

[dom14]

I dunno, I get the theory of thermostat keeping it that way..But my rig did the same with an old and a new thermostat. Going on a long downhill run it'd cool down a bit. My old Hilux did the same. They'd do the same if I just left them idling for ages, they'd just keep cooling down slowly. I don't know if once open, they don't close fully until a certain point or what, but it hasn't worried me.

What I have noticed now is that the auto choke (which I've had issues with previously, but thought i'd adjusted it enough to sort it) I believe is coming back on after a drive in cold weather, as it idles high for a bit when I come back to a standstill until the carby seemingly warms up a bit again and the idle lowers. Might wind the auto choke off a bit further.

Yeah, playing with the auto choke can help during the Melbourne winter, or any season in Melbourne, considering we tend to get all four seasons in a single day sometime.
But, RB30 and TB45 electric auto choke is not that smart or effective all the time. Auto choke opens up by heating bimetal coil electrically via alternator trigger line activated auto choke relay, not by responding to engine, carby or intake air temperature. Once the auto choke flaps are opened, it tend to stay that way. AFAIK, the the bimetal spring doesn't unwind itself in cold weather to cause the mixture to become richer. This is why sometime it can help turning the auto choke either way, depending on the weather/climate.
It is possible to improve the auto choke further to make it more "intelligent" to respond to intake air temperature and engine temperature, but I reckon the effort is probably put into a better use with an EFI conversion.

[dom14]

Having just fitted an extra water temp gauge, I can tell you
the after market gauge and the Ecu-Talk are pretty even
BUT when the OE dial shows the motor at running temp it is in fact
only 60-70 degrees on the gauges, well below my 85-88 operating temp
Hope that made sense lol

So, I shouldn't take the OE dial reading as accurate?
I do have an aftermarket coolant temperature gauge with an alarm buzzer, but have never got around to install it.
May be it's about time I install it.

[Throbbinhood]

Once the auto choke flaps are opened, it tend to stay that way. AFAIK, the the bimetal spring doesn't unwind itself in cold weather to cause the mixture to become richer. This is why sometime it can help turning the auto choke either way, depending on the weather/climate.

Thanks for the info Dom. Hmm, interesting. Might have to do some tinkering. Something's definitely going through a hot/cold phase though, just not sure what. Anyway, I think you've had enough of my hijacking your threads :P

[Throbbinhood]

So, I shouldn't take the OE dial reading as accurate?
I do have an aftermarket coolant temperature gauge with an alarm buzzer, but have never got around to install it.
May be it's about time I install it.

The OE gauge isn't very accurate, and the ones that are are still lazy. I've installed a gauge, with the reading coming from the top hose. It's much faster to respond and gives me a much better idea of what's going on.

[dom14]

Thanks for the info Dom. Hmm, interesting. Might have to do some tinkering. Something's definitely going through a hot/cold phase though, just not sure what. Anyway, I think you've had enough of my hijacking your threads :P

Nah, it's good you brought it up. As far as hot/cold hiccups with RB30, I reckon you explained it pretty well above with RB30 carbies are prone to quirks with sudden weather changes. It's probably not possible make them run perfect in every weather situation. Probably, some tinkering with the choke and tuning may be necessary from time to time.

[jay see]

I had the same issue with my tb45. Thermostat wouldn't close all the way, stayed open about 2 mm. Once replaced all good. Just got back from driving around in tempts that didn't pass 8 degrees during the day and tempts were fine.

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