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[kwfulton427]

I know some efi's vary the fuel/air mixture based on the temp of the engine... is this the case for a TJ? and if so, can the sensors be changed to run at a cooler temp? say, 160 or 180?

[Hoodoo]

The sensor varies the mixture over the entire operating range of the engine. If you want the normal operating temperature to alter, you'll have to get a thermostat rated at a different temperature to the one currently in the vehicle.
 Regards,

[Mike Pavelin]

:? What are you trying to achieve?

[Dingo]

A large backfire with flames

[Anonymous]

I've tried Encona fuelled curries for that effect...

[Dingo]

How do you get them in the tank, Funnel?

[kwfulton427]

lets say I put a 160 degree thermostat in... would this cause the fuel mixture to run rich because the sensor thinks the engine hasn't warmed up yet?

[Bubba]

noooo dont mess you wont gain anything worth having

[greggmo]

there are better ways of wringing a bit more out of yer 4 popper. throttle boddy spacer, k&n and so on.

[Dingo]

More fuel and less air wouldn't make it go any better, think about a carbed engine, imagine its warm and then put the choke on. Wont go, but it'll use a lot more juice. More air less fuel is the way to go. I think.

[chrisjones]

More air AND more fuel is the way to go!

[Mike Pavelin]

Won't make any noticable difference to performance. Engines are designed to work most efficiently at 180-190 so don't mess with it. If it runs too cool you could actually lose power.
The fuelling is controlled by the Jtec engine controller based on a set of data (or map) which is then constantly adjusted based on information from all the sensors on the engine, but the main player is the upstream oxygen sensor. Basically, once the engine is at operating temperature, the system reduces the fuelling until the sensor detects oxygen in the exhaust gases, then begins to ramp up the fuel until the oxygen disappears, then reduces it, increases etc etc... in an endless cycle. The only best way to get more power is to improve the engine's breathing, i.e. make it easier to get more air in and get rid of exhaust gases more efficiently. This could be through a larger throttle body, less restrictive air filter, forced induction or whatever, plus a more efficient exhaust system at the other end. If there is more oxygen available, the engine management will provide more fuel to get rid of it, and bingo! more power.

[Dingo]

Kind of what I was thinking , but on a more technical level, well explained Doc.

[kwfulton427]

thanks for the info...

i'd like to take a poll... what temp do your TJs actually operate at?

mine sits steady at 210

[Manda]

210? I presume that's farenheit?

Mine sits just a smidge under 100c.

[Anonymous]

~100c unless the rad is blocked

[kwfulton427]

yeah, its 210f (bout 100c)

[Mike Pavelin]

It should hover around the 210/100 mark