Open/closed loop coolant temp?

[CSaddict]

I need to know at what temp does a 95 xj go into closed loop? I need to know exactly or if you know what the coolant temp ohms is, that would work too.

[XJLI]

idk if this is exactly what you need, from my FSM:

Thermostat Opens
Starts .............................................. 195  F (90  C)
Fully Open ......................................... 218  F (103  C)


i'll dig deeper in my FSM after dinner to try and find that ohm reading.

[Dr. Thunder]

I think it would go into closed loop before the thermostat opens at 195.

[CSaddict]

Yeah, I need to know the temp the ecu needs to see before it allows cold loop. I am trying to force it back to open loop with a Hobb switch and a potentiameter.

And my T stat opens at 165.

[Dr. Thunder]

I thought a hobb switch was to prevent overboosting? How does that play a role in the cooling system.

I'd have to guess at 165 it's not even entering closed loop. I know in the LT1 world people need to get a tune when they throw a 160 thermostat in because their cars were stuck in open loop the entire time getting horrible gas mileage.

[XJLI]

i cant find the temperature, but im fairly sure the sensor operates at 5 ohms. ill keep digging.

[XJLI]

the FSM is calling 180F "operating temp." maybe thats where it goes into closed loop?

[Dr. Thunder]

Kind of a crude way of doing but hear me out. If you were to unplug the temp sensor while the jeep was warmed up and in closed loop there would be a differnence in idle, couldn't you figure out at what voltage the temp sensor started to allow closed loop by unplugging it every 10 or 20 seconds while the jeep was getting warm?

So basically let the jeep start to warm up and once the temp started to get up there (maybe around 140) start unplugging the temp sensor listening for a change in idle, if nothing plug it back in and try again until you hear the change. Once you hear the change you know the jeep just went into closed loop and you could take the voltage it switched over at.

[Dr. Thunder]

Jan 22, 2009 19:14:40 GMT -5 XJLI said:

i cant find the temperature, but im fairly sure the sensor operates at 5 ohms. ill keep digging.

Don't you mean volts?

[Dr. Thunder]

This may help a little. 80*C is = 176*F

[CSaddict]

Jan 22, 2009 19:09:45 GMT -5 Dr. Thunder said:

I thought a hobb switch was to prevent overboosting? How does that play a role in the cooling system.

I'd have to guess at 165 it's not even entering closed loop. I know in the LT1 world people need to get a tune when they throw a 160 thermostat in because their cars were stuck in open loop the entire time getting horrible gas mileage.

Its not to prevent overboosting. The ECM has enough injector control to fight off my FMU in boost and bring me back to 14.7ish. That is too lean. So if I am cruising on the highway and building boost but am hardly into the throttle it will be lean. If I stomp it and the ECm see WOT it diverts to open loop and lets my FMU do its job. I tried to divert TPS signal like we did on Pete's Wrangler and it worked for his but mine being an auto wants to downshift.

So I am going to try to use the hobb switch to switch the CTS out of warm range to drop it back into open loop.

Either that or I am building an AW4 shift box and eliminate the computer for shifting.

[XJLI]

i meant resistance.... as far as the correct operating voltage i'll guess its 4.5V. its hard to tell since it worded to test the system, and theres nothing there that says exactly what it should be.

[CSaddict]

Jan 22, 2009 19:31:41 GMT -5 Dr. Thunder said:

This may help a little. 80*C is = 176*F

You rock.

[Dr. Thunder]

Jan 22, 2009 19:32:34 GMT -5 CSaddict said:

Jan 22, 2009 19:09:45 GMT -5 Dr. Thunder said:

I thought a hobb switch was to prevent overboosting? How does that play a role in the cooling system.

I'd have to guess at 165 it's not even entering closed loop. I know in the LT1 world people need to get a tune when they throw a 160 thermostat in because their cars were stuck in open loop the entire time getting horrible gas mileage.

Its not to prevent overboosting. The ECM has enough injector control to fight off my FMU in boost and bring me back to 14.7ish. That is too lean. So if I am cruising on the highway and building boost but am hardly into the throttle it will be lean. If I stomp it and the ECm see WOT it diverts to open loop and lets my FMU do its job. I tried to divert TPS signal like we did on Pete's Wrangler and it worked for his but mine being an auto wants to downshift.

So I am going to try to use the hobb switch to switch the CTS out of warm range to drop it back into open loop.

Either that or I am building an AW4 shift box and eliminate the computer for shifting.

Ahh ok, so your going to use the hobb switch to look for boost, when it does it will override the cts to make the computer think open loop hence richening up the system? Smart thinking

[CSaddict]

Do you have the link for this picture?