[ask] Running Lean = Hot temp ?

[Hikaru]

Dear all

is that true if running a lean AFR causing engine temp higher than the normal AFR?
can some one explain it to me why

thanks

Topic

[Kevin Criswell]

It is true that a lean mixture burns much hotter than a rich mixture.

What is the issue you are having?

[Hikaru]

[quote=”Raistian77″ post=78898]It is true that a lean mixture burns much hotter than a rich mixture.

What is the issue you are having?[/quote]

I have problem with fuel economic
its to poor, about 6 km per liter or 14.1129 mpg

my car 1500cc toyota soluna 2000 AT (AL50) 5A-FE
when the emission (AFR test) test it mark 0.99 in lambda (still getting the 1:6 (its about 1:12 before))
now i want to try more leaner AFR maybe about 1,2 or 1,4 in lambda

or any other suggestions for my problem

what i have try
1. Tune up and carbon clean
2. Check TPS
3. Check MAP sensor
4. Check ISC (Cleaning inner part)
5. Check for vacuum leak
6. Check O2 sensor (this one im not sure, 0 V at off, and 13,xx V at ACC)

thanks

[dan]

the ideal A/F ratio is 14.7 parts air too 1 part fuel 14.7/1 this is known as a storchometric air fuel ratio, the smaller the number the richer, the higher the number the leaner…

running lean causes combustion temperatures too increase, this can cause engine temperatures too also increase beacuse of the increase in combustion temps… in cases of extreme lean conditions spark knocking can accure…

looks like you have covered all the bases but i would try pulling codes and see what they say, they may lead you in more of the right direction…

[Kevin Criswell]

[quote=”Shikaru12″ post=78908][quote=”Raistian77″ post=78898]It is true that a lean mixture burns much hotter than a rich mixture.

What is the issue you are having?[/quote]

I have problem with fuel economic
its to poor, about 6 km per liter or 14.1129 mpg

my car 1500cc toyota soluna 2000 AT (AL50) 5A-FE
when the emission (AFR test) test it mark 0.99 in lambda (still getting the 1:6 (its about 1:12 before))
now i want to try more leaner AFR maybe about 1,2 or 1,4 in lambda

or any other suggestions for my problem

what i have try
1. Tune up and carbon clean
2. Check TPS
3. Check MAP sensor
4. Check ISC (Cleaning inner part)
5. Check for vacuum leak
6. Check O2 sensor (this one im not sure, 0 V at off, and 13,xx V at ACC)

thanks[/quote]

If you have a lambada of .99 you are darn near perfect. 14.7 to 1 is ^1.00, not sure if you can get anywhere away from that. The computer is going to fight you to get back to a lambada of 1.00.

[Hikaru]

[quote=”13aceofspades13″ post=78932]…

looks like you have covered all the bases but i would try pulling codes and see what they say, they may lead you in more of the right direction…[/quote]

I haven’t check for code for this problem
but
About 2 year ago i try to diagnose the car by engine check because of hesitation and low torque
(jumper TE1 – E1 if im not mistaken)
it resolve 42 (4 blink and 2 blink in a row)
42 error code possibility:
– indicate Knock Sensor (Soluna didn’t have this sensor)
– indicate MAF/MAP sensor (Soluna didn’t have MAF but have a MAP, I check and OK)
– indicate IIA problem (Distributor Assy) (Check this one take apart to clean it up and check every part and reassembled I didn’t find any problem just very small crack at the coil cassing)
– indicate ECU problem (physically not damage, i don’t know about he firmware)

than I found out that leaking vacuum pipe PCV and MAP pipe, and the problem solve for the hesitation and torque and also the check engine blink for normal.
but now it become more economically non friendly
and 1 more problem, now the engine have 3 stage rpm instead of 2 stage when warming up.
normally warming at 1500 rpm than go to 850 rpm when idle
now warming at 1200rpm and increase slowly to 1500 rpm than go to 1000 rpm idle after about 2 minutes go to 900 rpm and constant at 900 rpm idle i don’t know if this related to the very poor fuel economic.

thanks

[Author]

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