Thermostat temps & closed/open loop fuel settings.

Comet #2

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Thermostat temps & closed/open loop fuel settings.	Permalink

Am wanting to lower the engine operating temp by fitting a lower temp thermostat ... without causing computer hassles with fuel mixes. Has anyone had any success getting factory computer settings changed ... and who by ??? Vehicle is a 98 4.0l XJ Thanks ..... __________________

threeEs99

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I've never known it to work properly. Maybe other members may. The factory opperating temp is the engins best working opp temp. Are you having cooling problems? __________________ 99 sport. rust bucket, DD, 3 car seats 04 wj (w/3 car seats too) DD duty for the lady

GrumpysXJ

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I believe the only way to run a lower operating t-stat is to buy a ecm chip or power programmer. I do know some people that have a aux elec. fan and they ran a switch on it so it will run all times to help keep thier XJ at 210 degrees. Alot of members on here have installed hood vents to help in the cooling dept.

-- Edited by GrumpysXJ on Tuesday 21st of April 2009 10:27:34 PM

-- Edited by GrumpysXJ on Tuesday 21st of April 2009 10:28:02 PM

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Comet #2

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threeEs99 wrote:

I've never known it to work properly. Maybe other members may. The factory opperating temp is the engins best working opp temp. Are you having cooling problems?

Agree threeEs99 ..... Lower thermostat without changing PCM settings would be a fail due to the open/close loop settings - and richer mix until preset temp was reached ... hence wanting to change the factory setting to match about a ... 185' F thermostat.

IMHO the factory operating temp may be the best for northern hemisphere legislated fuel and emission requirements ... but not nescessarily the best for southern hemisphere peace of mind motoring ... too close to cooking point for me.

No cooling problems ... yet ( according to chrysler specs ) ... About to overhaul the cooling system for its next 5yrs of operation ... and a lower op temp would be a nice addition.

GrumpysXJ wrote:

I believe the only way to run a lower operating t-stat is to buy a ecm chip or power programmer. I do know some people that have a aux elec. fan and they ran a switch on it so it will run all times to help keep thier XJ at 210 degrees. Alot of members on here have installed hood vents to help in the cooling dept.

-- Edited by GrumpysXJ on Tuesday 21st of April 2009 10:27:34 PM

-- Edited by GrumpysXJ on Tuesday 21st of April 2009 10:28:02 PM

Thanks GrumpysXJ ... Chrysler Dealers over here state they dont have the facility to change factory settings and local PCM exchange/repairers can only load new chips with existing chip info ... so am looking for stateside locations with the ability to change the "0"s and "1"s around.

Lots of mucking around over here with different electric fans and controls .., chopping holes in bonnets .., radiator types etc ... some ideas work reasonably well ... some dont ... depending on driver and vehicle use.

Not in favour of bonnet scoops as they reduce even more ... the pathetic amount of airflow down past the gearbox.

From my reading ... none of the modifications deal with the fact that the engine is being forced to run at peak/so called - best operating temperature constantly .... they just make the bonnet (hood) cooler to touch when opening .... and in other cases provide slower heat buildup when under low speed load ...

Its all a bit like packing newspaper in your hat band ... the hat size is still too big for your head ...

What I want to achieve may not be possible but am exploring the idea and looking for a U.S. contact with the expertise.

Thanks for the replies.

-- Edited by Comet #2 on Wednesday 22nd of April 2009 07:20:27 AM

-- Edited by Comet #2 on Wednesday 22nd of April 2009 07:23:31 AM

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aci4369

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What year is your XJ?

If you have a 97+ this will not apply.

I have seen people put a 180 thermostat in their XJ's during the summer to make them run cooler. I don't know about the negative side affects of this though. This is on pre-97 XJ's though. The 97+ XJ have a different cooling system and don't need this done.

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ChevelleSSLS6

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hmmm... if you don't have any issues (running hotter than normal, leaks, or if hoses are squishy or dry rotted, etc, etc, etc...), I see no need to change anything on a basically stock engine.

When upgrade time comes, the two best ones are either the one I got (have yet to install it, presently working on other things on the Jeep) is the proliance (was modine) heavy duty radiator, or Motion Offroad offers another heavy duty radiator.

I like the Hesco thermostat housing, and plan on purchasing their water pump when the time comes.

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Comet #2

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aci4369 wrote:

What year is your XJ?

If you have a 97+ this will not apply.

I have seen people put a 180 thermostat in their XJ's during the summer to make them run cooler. I don't know about the negative side affects of this though. This is on pre-97 XJ's though. The 97+ XJ have a different cooling system and don't need this done.

Its a post update model.

Negative effects:
Based on the OE workshop manual information and past experience ... Increased fuel consumption ... which might be a situation that just has to be continued to be accepted ...... @ average $6.oo (Oz) per gallon

ChevelleSSLS6 wrote:

hmmm... if you don't have any issues (running hotter than normal, leaks, or if hoses are squishy or dry rotted, etc, etc, etc...), I see no need to change anything on a basically stock engine.

When upgrade time comes, the two best ones are either the one I got (have yet to install it, presently working on other things on the Jeep) is the proliance (was modine) heavy duty radiator, or Motion Offroad offers another heavy duty radiator.

I like the Hesco thermostat housing, and plan on purchasing their water pump when the time comes.

Havent had any major issues ... because of regular servicing maintenance / a preference for night travel when the air temp/ground surface is cooler / and temporary use of a lower thermostat during our summer season.

None of the jeeps owned over the past 12yrs have been daily drivers ... All have been been long range travel vehicles for monthly fishing/hunting trips ... with a 300 - 800+ mile destination points depending on activities ... Both have been good vehicles used in the above manner, with no real faults (electronics aside) - even when towing ... This ones age and intended, increased daytime summer use is the reason for exploring more / better cooling options other than constantly running additional electric fans.

Leave it alone till it breaks is a fine policy .... however fitting a new water pump 6weeks after the radiator or something else is not my way .... it will all be done at the same time.

Unlike the U.S. ... jeep parts arent as common as potatoes over here and the nearest parts supplier to me ... with anymore than an 80% chance of having a needed part in stock ... is about 400 mile away ... Remote parts of Oz are even worse ... so my policy here is - order and replace something before its totally worn out - and leaves you stranded somewhere ( vehicle brand regardless )

Better radiator is definitely being fitted ... as are a few other items ... to ensure "trouble free' driving ...

Owning a jeep over here for use other than as a 1/1 scale remote control rockcrawler can be an interesting experience.

One just has to accept the lack of design for our long distance travel conditions and drive accordingly / improve components where possible.

Im surprised tho - that after all the time the 4.0l XJ has been available ... with overheating issues, even in the northern hemisphere ... that the computer reprogramming info, and any benefit if any, isnt common knowledge with a yes or no answer.

My option to upgrading to get another 5yrs + out of the vehicle is to go and waste a heap of money buying some tacky, generic, boring, overpriced japanese thing with a 5yr warranty ..... and thats not a likely scenerario .... been there and done that - when they used to be good vehicles .....

-- Edited by Comet #2 on Thursday 23rd of April 2009 07:33:50 AM

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aci4369

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So you are trying to replace the cooling stuff all at once so that you don't have problems in the future? This is a good idea, I am just trying to get a grasp of what you are trying to do and what you are asking. There is a lot of good info on this post that Lead started a while ago. Some of the things that are discussed might not be available to you but maybe if you know what you want we could help you get it shipped to you.

Here is the: LINK

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tjhawk

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I bought my 93 XJ new when I lived in Phoenix which has over 100 degrees 24 hours a day for 6-7 months of the year. I never had any cooling problems and even in rush hour traffic I never saw my temps get hotter than 220 and that was when sitting still for over 1 hour with the AC on in 120 degree heat.(ironically 220 is normal operating temp for some modern imports). The only thing different I had on my XJ was the desert protection package which was a HD cooling rad and a seven blade fan with the HD clutch. Your electric cooling fan automatically turns on with the AC or when temps reach above 220. You can rig a switch to fire this manualy using a switched ground(with a diode to prevent feedback to the ECM while at the same time turning on the relay).
In my opinion the old school idea of cooler is better IS WRONG!!! Engines need to warm up fast and stay there. This gets out moisure, crankcase vapors keeps the metal at a constant state of expansion which is good for seals and gaskets. The days of the slower reving, cooler running engines is gone and it has been proven that engines that warm up fast and stay hot last longer than cooler running engines do. Just look at your milage you get out of a vehicle these days. In the days of old if you got 100k out of an engine you were doing great but it probably needed to be rebuilt soon after. Now days people are getting mulit 100K miles on their engines and it still running strong. Of course the metals and oils are better but fuel injection and higher temps helped too.

My 93 XJ has 190k on it and it is till running strong. Uses(also leaks a bit) 1/2 qt every 3k miles, oil pressure is still a steady 60 psi at cruise about 40 at idle. I have spent less than $1500 in repairs to date since new and that includes tires and brakes! This has been the best auto I have ever owned for problem free driving. Mine is all stock with the only mod is an OE style aftermarket aluminum rad I got new off of ebay for $75. Its a wide core not a two core so it flows alot more coolant than my old one ever did.

Just an FYI my XJ has a 195 degree t stat and my temps fluxuate from 200-210 depending on the time of year in WI. Putting in a 185 will maybe save you what 10 degrees. Like that does anything. Also closed loop occurs long before the engine temp gets to 210. It times out after the engine reaches 140 degrees or when the Oxy sensor reaches something like 400 degrees and starts giving feedback about the state of the exhaust emissions.

As for the Ozzie getting parts from 400 miles away you must be way in the outback. I'd hate to have to second guess when I would need a part or repair....thats crazy.

-- Edited by tjhawk on Thursday 23rd of April 2009 02:19:04 AM

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Comet #2

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Thanks aci4369 ... for the parts supply offer and that thread link.
This is all getting a bit longwinded now ..... Basically all I want to do ... besides replacing all cooling items at once which is an easy process ... is undertake some ... what should be simple mods without extreme vehicle component conversions.
Having a new chip fitted with the desired temp settings should be a simple process these days I would have thought ... but perhaps it wont be.
tjhawk wrote:
I bought my 93 XJ new when I lived in Phoenix which has over 100 degrees 24 hours a day for 6-7 months of the year. I never had any cooling problems and even in rush hour traffic I never saw my temps get hotter than 220 and that was when sitting still for over 1 hour with the AC on in 120 degree heat.(ironically 220 is normal operating temp for some modern imports). The only thing different I had on my XJ was the desert protection package which was a HD cooling rad and a seven blade fan with the HD clutch. Your electric cooling fan automatically turns on with the AC or when temps reach above 220. You can rig a switch to fire this manualy using a switched ground(with a diode to prevent feedback to the ECM while at the same time turning on the relay).

l The temps you mentioned are reasonably similiar to what we are used to in most parts of the country over here. A new vehicle such as yours was ... should not have had any problems ... however the use you mentioned is somewhat different to regularly towing half a ton or more at highway speeds for 6 or 8 hours whilst drawing 110'F air through the radiator.
l Nothing ironic about that temp in a screaming, fast and foolish drifting, new import, but it is a bit ironic that one would think it the correct temp for the reliable ol eggbeater 4.0l i6 given its heritage.
l That " desert protection package" might have been a good option over here - unless the barely adequate cooling system provided from new on so called Oz models ... is that package.
l An electric fan override was one of the first things done as an obvious improvement to the system.

In my opinion the old school idea of cooler is better IS WRONG!!!
Engines need to warm up fast and stay there. This gets out moisure, crankcase vapors keeps the metal at a constant state of expansion which is good for seals and gaskets. The days of the slower reving, cooler running engines is gone and it has been proven that engines that warm up fast and stay hot last longer than cooler running engines do. Just look at your milage you get out of a vehicle these days. In the days of old if you got 100k out of an engine you were doing great but it probably needed to be rebuilt soon after. Now days people are getting mulit 100K miles on their engines and it still running strong. Of course the metals and oils are better but fuel injection and higher temps helped too.

Apart from that emphatic first line ... I agree with all of that when applied to todays new motors ... and even an old motor shouldnt be run too cold as condensation is an issue.

However IMHO peak operating temps/conditions should only be reached under load ... not zipping down to the shops 10minutes away with only the driver in the vehicle. Leaves way too little safety margin in regard to overheating under a load ... and I'll refer to every jeep cooling mod Ive read in the last two years as witness to that.

My 93 XJ has 190k on it and it is till running strong. Uses(also leaks a bit) 1/2 qt every 3k miles, oil pressure is still a steady 60 psi at cruise about 40 at idle. I have spent less than $1500 in repairs to date since new and that includes tires and brakes! This has been the best auto I have ever owned for problem free driving. Mine is all stock with the only mod is an OE style aftermarket aluminum rad I got new off of ebay for $75. Its a wide core not a two core so it flows alot more coolant than my old one ever did.

$ 75 Radiator ... Dammn you blokes have it easy. Checkout ebay.com.au for what we have to contend with ...

Just an FYI my XJ has a 195 degree t stat and my temps fluxuate from 200-210 depending on the time of year in WI. Putting in a 185 will maybe save you what 10 degrees. Like that does anything. Also closed loop occurs long before the engine temp gets to 210. It times out after the engine reaches 140 degrees or when the Oxy sensor reaches something like 400 degrees and starts giving feedback about the state of the exhaust emissions.

l Hmmmm .... average Appleton summer temp 69'F ... good idea moving to a cooler climate as your vehicle and cooling system got older ...
l The 10' will put my vehicle on par with yours given the difference in average temps for our locations ... and allow me to be almost as unconcerned about cooling issues in an old car ... as you.
l FYI ... A read of pages 29/30 and others in sect 14 of the XJ manual available on this excellent site will help in regard to understanding temps/sensors/loops.

As for the Ozzie getting parts from 400 miles away you must be way in the outback. I'd hate to have to second guess when I would need a part or repair....thats crazy.

l Outback ... ... thats way west of me ... Im only about 300 miles from the coast as the crow flies.
l Local chrysler dealers ( i.e. 120 mile away ) dont stock XJ fanbelts, c-clips, rad hoses, CKS sensors or anything of much use. Local aftermarket car part suppliers scratch their heads and say "sorry mate - might be able to order it for you." ......... Internet access to jeep forums, parts manuals and suppliers etc .... has been a godsend ... although chrysler dealers here dont like you quoting part numbers at them ...
l Crazy ??? ... In reality there is very little second guessing of needed parts ... Mechanical items or items that wear have a general life expectancy depending on vehicle use / quality of maintenance ... Its only the crap electronics in all new vehicles, that may or may not work - the next time you go to start it.

Just in case ... ( especially after tjhawks response ).

This is not a complaint thread about XJ's ... wouldnt still be driving the old thing if I didnt like it
Its a hunt for other ways of making it better suited for the use I give it ..... No different to some of you needing those 4" suspension lifts which I just shake my head at ...

-- Edited by Comet #2 on Thursday 23rd of April 2009 06:43:14 AM

-- Edited by Comet #2 on Thursday 23rd of April 2009 06:47:37 AM

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aci4369

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So do you think that info supplied answered your questions? Or are you still looking for more? __________________ '99 XJ, 5.5" lift, 33" MT's '11 Dodge Charger I miss the days that they made toys that could kill a kid. Support our Troops My Pics and Specs My Build Thread

tjhawk

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"Hmmmm .... average Appleton summer temp 69'F ... good idea moving to a cooler climate as your vehicle and cooling system got older ... "

I lived in Phoenix, Arizona for most of my XJ's life. Think of a place like The Great Victorian desert or Gibson desert region for temps like mine used to endure. As for cooling your trans better I have an oil cooler (for the race car) that has an electric fan attached to it so you can mount it anywhere and given the lack of space in the front radiator area the idea of a relocated cooler isn't such a bad idea. Also a large coolant to oil heat exchanger would work nicely as well.(like ones used on the big diesels) I actually have one I used to use to provide hot shower water when we would go camping in the mountains. It used the hot water from the the engine to heat the shower water. Worked nicely I might ad. If you want I can call up some of my friends in the desert southwest and locate you the heavy duty "desert package" parts and ship them. I have a friend who lives in Newcastle and another who lives in Brisbane and we are always sending stuff across the big pond. How is customs on used car parts? Any duty to be paid?

As for the comment about only heating up only under load...my only answer is there are plenty of ways to make a vehicle get hot fast and plenty of ways to make it stay there. I can't remember the last time I saw a Honda Civic pulling a load.....LOL.
We also have stricter emission standards here is the states which also helps drive the temps up.
In Tokyo, Japan they have the strictest emissions of all. They have to have ZERO tail pipe emissions from start up. Most cars there have catalytic converter pre-heaters that light the cats up hot from the first rotation of the key so anything that might be bad gets fried before it ever hits the air. They also have a law that states that a cars end of life cycle is at 36,000 miles. This means you have to either crush it or sell it over seas because you cannot drive it anymore. Talk about strict. Then again its one of the most polluted modern cities in the world.

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Comet #2

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aci4369 wrote:
So do you think that info supplied answered your questions? Or are you still looking for more?

The info is all great for confirmation / ideas to consider and muchly appreciated.

Am currently waiting on e-mail responses from PCM repairers about my query about reprogramming to accept a different thermostat.

Any useable info I get ... I will pass on here.

tjhawk wrote:

"Hmmmm .... average Appleton summer temp 69'F ... good idea moving to a cooler climate as your vehicle and cooling system got older ... "

I lived in Phoenix, Arizona for most of my XJ's life. Think of a place like The Great Victorian desert or Gibson desert region for temps like mine used to endure. As for cooling your trans better I have an oil cooler (for the race car) that has an electric fan attached to it so you can mount it anywhere and given the lack of space in the front radiator area the idea of a relocated cooler isn't such a bad idea. Also a large coolant to oil heat exchanger would work nicely as well.(like ones used on the big diesels) I actually have one I used to use to provide hot shower water when we would go camping in the mountains. It used the hot water from the the engine to heat the shower water. Worked nicely I might ad. If you want I can call up some of my friends in the desert southwest and locate you the heavy duty "desert package" parts and ship them. I have a friend who lives in Newcastle and another who lives in Brisbane and we are always sending stuff across the big pond. How is customs on used car parts? Any duty to be paid?

As for the comment about only heating up only under load...my only answer is there are plenty of ways to make a vehicle get hot fast and plenty of ways to make it stay there. I can't remember the last time I saw a Honda Civic pulling a load.....LOL.
We also have stricter emission standards here is the states which also helps drive the temps up.
In Tokyo, Japan they have the strictest emissions of all. They have to have ZERO tail pipe emissions from start up. Most cars there have catalytic converter pre-heaters that light the cats up hot from the first rotation of the key so anything that might be bad gets fried before it ever hits the air. They also have a law that states that a cars end of life cycle is at 36,000 miles. This means you have to either crush it or sell it over seas because you cannot drive it anymore. Talk about strict. Then again its one of the most polluted modern cities in the world.

Yeah thanks for all that ....

Dont need to think about our "desert" temps ... 300 odd mile west of Newcastle out here in our cotton growing belt ... and they are the same temps ... and hotter on occaision ... just might be a week or two less of them during summer.

Had another scrounge through the info I have - and you provided ... The U.S. "heavy duty" cooling system appears to be what was fitted on Aust sold, post 97 updates as the "standard" cooling system to make them suitable for general use here. No chrysler jeep XJ optional cooling systems here bar what we arrange ourselves for "heavy duty" use.

Shipping ... Under $1000 (aus) item cost and by mail seems to be the most effective by those who have had gear shipped over.

Quite a few good suppliers of parts here tho ... just not as close or as common as what you have available.
Thanks for the replies .....

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ChevelleSSLS6

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Comet #2 wrote:
ChevelleSSLS6 wrote:

hmmm... if you don't have any issues (running hotter than normal, leaks, or if hoses are squishy or dry rotted, etc, etc, etc...), I see no need to change anything on a basically stock engine.

When upgrade time comes, the two best ones are either the one I got (have yet to install it, presently working on other things on the Jeep) is the proliance (was modine) heavy duty radiator, or Motion Offroad offers another heavy duty radiator.

I like the Hesco thermostat housing, and plan on purchasing their water pump when the time comes.

Havent had any major issues ... because of regular servicing maintenance / a preference for night travel when the air temp/ground surface is cooler / and temporary use of a lower thermostat during our summer season.

None of the jeeps owned over the past 12yrs have been daily drivers ... All have been been long range travel vehicles for monthly fishing/hunting trips ... with a 300 - 800+ mile destination points depending on activities ... Both have been good vehicles used in the above manner, with no real faults (electronics aside) - even when towing ... This ones age and intended, increased daytime summer use is the reason for exploring more / better cooling options other than constantly running additional electric fans.

Leave it alone till it breaks is a fine policy .... however fitting a new water pump 6weeks after the radiator or something else is not my way .... it will all be done at the same time.

Unlike the U.S. ... jeep parts arent as common as potatoes over here and the nearest parts supplier to me ... with anymore than an 80% chance of having a needed part in stock ... is about 400 mile away ... Remote parts of Oz are even worse ... so my policy here is - order and replace something before its totally worn out - and leaves you stranded somewhere ( vehicle brand regardless )

Better radiator is definitely being fitted ... as are a few other items ... to ensure "trouble free' driving ...

I like that approach... if the old part is still good, you could hang on to that just in case the new part fails sooner than expected. I'm personally debating if I should get a new coolant pump when I put in the new radiator. New hoses and clamps, thermostat, and adding a Hesco thermostat housing are planned for it 100%.

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LEAD_NOT_FOLLOW

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Ok I've kept my mouth shut thus far but I need to set a few things straight...

First Off...

The Eprom chip in the ECU is NOT, I repeat NOT programmable. You can not just swap in an alternative chip into it. The only way to alter any DME functions on the ECU is to run a "piggyback" system.

Look into the UniChip system. I'm not sure what year your 4.0L is, and what ECU your using but 91-92 OBD1 models have to be hard wired due to the ECU pinouts being a bit different, the 92+ is "plug and play". It's only 8 wires so not to bad of a job to install.

Secondly...

The purpose of the engine thermostat is not to keep the engine cool. Its purpose is to maintain a specified minimum temperature. Once that specified temperature is exceeded, the temperature is no longer controlled by the thermostat.

A t-stat is intended to keep the engine warm, and NOT to help it cool. Normal running temps for a 4.0L are higher than either a 180 or 195 t-stat. Thus, regardless of which one you have installed, when it's working correctly, and the engine is warmed up, the 'stat is WELL PAST it's full-open temp.

Putting in a lower t-stat only means the t-stat opens SOONER during the warm up cycle, thus slowing down the warm up. It does nothing to lower the temp once the engine is fully warmed up, as it's all the way open, be it a 180 or a 195.

You guys DO understand that, once an engine reaches the temp of the thermostat, the t-stat stays FULLY OPEN.

What this means is that, if you have a 180 t-stat in your vehicle, and your engine has been running for a while, an the temp guage reads "190" (as an example), then the t-stat is FULLY OPEN. If the guage reads "200", it's NOT any MORE open--it's the SAME amount of open.

The point of all of this is that lower temp t-stat will NOT make an engine run cooler, PROVIDED the cooling system, when fully warmed, will not allow the engine to run any lower than the t-stat temp.

Getting to the fuel debate and getting better MPG.

When the engine is "cold," the ECU operates what is called an "open loop" mode during which time the oxygen sensor input is not utilized to control fuel delivery.

There are two types of modes of operation: open loop and closed loop. During open loop modes, the engine does not monitor the O2 sensors and mixes fuel based on preset values. During closed loop modes, the engine monitors the O2 sensors and adjusts fuel mixture based on these inputs. Engine start-up, engine warm-up and key-on modes are all open loop modes.

I will tell you that I did find out a few things about the "warm up" mode. The first is that the park/neutral position switch is monitored. The engine adjusts idle based on this input (auto trans only). Second, once the engine warms up, the PCM starts to monitor the O2S sensors and goes into closed loop mode. The engine adjusts its fuel mixture based only on the first O2 sensor on 2 sensor equipped XJ's.

Based on my research and reading the stock ECU (PCM) for setting up my Motec here is the setting's for "warm up" mode.

I do know the OHM that the CTS (coolant temp sensor) sends at different temps however.

All degree's are in Fahrenheit.

212 (desired operating temp for my motor) - 185 ohms
160 - 450 ohms
100 - 1600 ohms
70 - 3400 ohms
40 - 7500 ohms
20 - 13,500 ohms
0 (startup) - 25,000 ohms

With that info, "warm-up" mode stops at around 180*, thus making your statements about a t-stat having any affect on controlling the ECU and the fuel delivery to your motor not true as they are all pre-set values anyways...

I can go more into it if you want to discuss it more. Not saying I'm an expert but with way to much $$ into my motor, and a lot of $$ into the cooling aspects of it I have done my research and know what does/does not work...

-- Edited by LEAD_NOT_FOLLOW on Tuesday 28th of April 2009 07:43:04 PM

-- Edited by LEAD_NOT_FOLLOW on Tuesday 28th of April 2009 07:43:45 PM

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Topic: Thermostat temps & closed/open loop fuel settings.