# Timing/ fuel mileage, KA motor



## Fastbird (Mar 3, 2010)

Anybody done any real world testing of initial timing vs. fuel mileage? Ive know the factory spec is 10 BTDC, but wondering if anybody has played with different initial settings and found better mileage.

Thanks


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## rogoman (Dec 16, 2004)

I've done similar testing on my 240sx KA24DE. As a result, changing the timing + or - by a few degrees did not make a marked improvement in MPG on my car. However replacing a marginal O2 sensor and insuring that coolant temperature is at the specified OEM spec does have a major impact on MPG.


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## Grug (Aug 20, 2009)

When you say a marginal O2 sensor, do you mean it was bad enough to trip the check engine light and a code? Or does that sensor still kinda' work (but not necessarily well) with no check engine light appearing.

That's the sensor plugged into the lower portion of the exhaust manifold...right?


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## rogoman (Dec 16, 2004)

In my case, the marginal sensor still worked with no check engine light. On my '91 240sx, there is only one sensor that's on the exhaust manifold.


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## Verga (Jan 31, 2010)

rogoman said:


> I've done similar testing on my 240sx KA24DE. As a result, changing the timing + or - by a few degrees did not make a marked improvement in MPG on my car. However replacing a marginal O2 sensor and insuring that coolant temperature is at the specified OEM spec does have a major impact on MPG.


What is the sprecified temp?

My thermostat is factory Nissan, so Id guess it is correct?

Good advice on the O2 sensor. 

I wonder if there is a way to check it?


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## rogoman (Dec 16, 2004)

The OEM temperature spec with a fully warmed up motor is 194 degrees F so you should be OK.

There is an ECU diagnostic procedure for the O2 sensor. However if you've got at least 40,000 MI on the O2 sensor, it's a good idea to change it; it's best to get an OEM unit.


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## Verga (Jan 31, 2010)

rogoman said:


> The OEM temperature spec with a fully warmed up motor is 194 degrees F so you should be OK.
> 
> There is an ECU diagnostic procedure for the O2 sensor. However if you've got at least 40,000 MI on the O2 sensor, it's a good idea to change it; it's best to get an OEM unit.



The 'Stat in the motor is not that warm, its only a 180ish stat. It is the original stat, but does have 218K on it. Maybe I should change it to the higher stat?

The O2 has 218k on it as well. Might as well change it. When you say OEM, I assume you mean get a sensor from Nissan?

Thanks


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## rogoman (Dec 16, 2004)

Thermostats do degrade over time and you end up with a colder running temperature. You probably should install a new one.

Yes, an OEM O2 sensor from a Nissan dealer. Since you're a member of this forum, print the home page of this forum and take it with you if you go to a Nissan dealer and ask for a discount; they'll generally give you a 10 to 15% discount. It's always worked for me.


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## Verga (Jan 31, 2010)

rogoman said:


> Thermostats do degrade over time and you end up with a colder running temperature. You probably should install a new one.
> 
> Yes, an OEM O2 sensor from a Nissan dealer. Since you're a member of this forum, print the home page of this forum and take it with you if you go to a Nissan dealer and ask for a discount; they'll generally give you a 10 to 15% discount. It's always worked for me.


Well I called a dealer and they wanted 138 and change for a O2 sensor.

Rockauto has them from 14 to 40 bucks??

Cant see that the OEM sensor is worth an extra bill?

Of the aftermarket sensors which is the best? 

Thanks


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## rogoman (Dec 16, 2004)

I had gotten an O2 sensor from Advance Auto about two years ago for around $40. It was a Bosch unit which I think might be OEM for the KA24; it had the proper connector end. It's been working good.


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## 95pickup (Jul 22, 2009)

NAPA=AUTOZONE-OREILYS HAS THE SAME O2 SENSOR AS NISSAN BUT FOR HALF THE PRICE. NISSAN JUST HAS THIER IN A NISSAN BOX AND CHARGES DOUBLE!


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## rdgerunr49 (Aug 8, 2009)

I had better results from Pacesetter Headers. I had them ceramic coated. I also have a K&N Aircleaner. Flex-fan dual 12 inch fans and E3 Spark plugs. I have the collector going into a 1 1/2 inch Catalytic converter and them coming out and going into a 2 inch Magnaflow 44 Muffler and finally exiting just behind the rear tires. I am getting about 30 MPG.




1992 Nissan D21 Hardbody (Kingcab)
KA24E
5 Speed


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## rdgerunr49 (Aug 8, 2009)

Fastbird said:


> Anybody done any real world testing of initial timing vs. fuel mileage? Ive know the factory spec is 10 BTDC, but wondering if anybody has played with different initial settings and found better mileage.
> 
> Thanks


I finally settled on 8 btdc and it works great. It got a little hot so I went with Flexfan dual 12 inch fans. Man that solved the problem and gave me a little more horsepower

1992 Nissan D21 Hardbody (Kingcab)
KA24E
5 Speed


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## zanegrey (Dec 5, 2005)

i do not beleive you can trick this engine to run better with timing..

if you have the bottom pulley at 8 degrees then the oil pump is probably a tooth off fooling you to think that it is 2 degrees off timing when in fact it is right on time..

you may advance the timing and seem to get a pepier response but it at the expense of added wear and tear and or gas mileage...


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## rdgerunr49 (Aug 8, 2009)

zanegrey said:


> i do not beleive you can trick this engine to run better with timing..
> 
> if you have the bottom pulley at 8 degrees then the oil pump is probably a tooth off fooling you to think that it is 2 degrees off timing when in fact it is right on time..
> 
> you may advance the timing and seem to get a pepier response but it at the expense of added wear and tear and or gas mileage...


Well as you know the oil pump cannot be put one tooth off because it isa compreesion gear setup. And yes it is truly 8 btdc. So believe it or not I know what I have done.


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## zanegrey (Dec 5, 2005)

the oil pump shaft can be a tooth off which drives the dizzy...


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## rdgerunr49 (Aug 8, 2009)

zanegrey said:


> the oil pump shaft can be a tooth off which drives the dizzy...


Yes you are right I was thinking down below. My bad. The dizzy would then show something that it was not.


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## tomas hayden (Dec 15, 2007)

lol...don't sweat it...that guys has had the truck of his for twenty some years ..

he knows them back to front..

i had my nissan truck at a stealership and they tried to charge me almost 3 k and the truck was not fixed..

zg came to my rescue and fixed the truck in 15 minutes ..

then he called the chamber of commerce ,bbb and the local news guy to tell them what the stealership was trying to do..

the stealership tore up the bill ,filled the tank with gas and offered to pay for relicensing it (beacuse it had been there so long)

i had to have it towed to them and drove it home after he fixed it when all those mechanics could not or would not..

he even said it was something simple ..


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## rdgerunr49 (Aug 8, 2009)

zanegrey said:


> the oil pump shaft can be a tooth off which drives the dizzy...


Okay This is my first rice burner. I am a diehard American Muscle fan. I have a question. I have a 240sx Ka24e engine and I want to put it in my truck how hard would that be?


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## zanegrey (Dec 5, 2005)

it is the same engine just configured differently..

those configurations make it hard to bolt right in..

the starters are different and i bekeive the oil dipstick is on the wrong side of the engine..


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## rdgerunr49 (Aug 8, 2009)

The dipstick is on the same side just more toward the front. I have the all the wiring for the engine but it was cut from the firewall. Can I use the existing engine loom but just splice it as I go? I was told that I would need the loom for the 240sx with the ECU. I am hoping I can use the one for my truck and just splice it in.


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## zanegrey (Dec 5, 2005)

if you are going to use the intake you will nedd the ecm and wireharness..

i did hear of some one trying to just splice it in but he had to have the ecm modified..

try.. www.ka-t.org :: Index for n e thing ka related


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