Exhaust Deceleration Popping Noise Solution!!

[MikeMurphy]

Exhaust backfire AND sudden surge of power after 5000rpm??? read on first!

OK. Well I have put some thought into this, and have read a number of posts here with people who share similar exhaust "problems" as I do.

For those of you who suffer from mild exhaust pipe combustion noise upon certain RPMs while decelerating, please continue reading.

My thoughts on the KA is that its a great engine and is pretty much rock solid for reliability. The thing however that seems to go on almost every "high milage" KA is the coolant temp. sensor which I understand has a direct effect on ignition timing.

Crazy ignition timing = crazy combustion timing = putt putt putt

Anyways, I dont KNOW this but those who participate in the poll should draw a fairly reasonable indication of the conclusion.

For those of you interested in one of the many interesting reads check this out. It is nothing special in particular with exception to the increase of power issue. http://northwestnissans.com/bo...18485

Thanks for your time.

-Mike MurphyPlease share your symptoms

[MikeMurphy]

hmmmm

[PhaneSoul]

ima try that.... when my car is runnin again

[89240sx]

Very interesting, so to tell if it is bad you drive the car around the block then let it idle and unplug the red plug and drive it.... So if Power increases while it is unplugged it's bad ? Maybe I'm not understanding however I will definately take a look at it.

[89240sx]

no responses? Maybe this thread should be moved?

[Aries]

when my car had a KA, it would not have a power surge, but upon deceleration would still experience post detonation due to a bad collant temp sensor and it's effect on the timing.This would ONLY happen after hard acceleration, or when left to idle fro long periods of time.

[89240sx]

Is there a way to test the actual sensor?

I'm not an uber leet car nerd but I can get my way around an engine comfortably... anybody have any specifics on testing ?

[Aries]

FSM + volt meter = good or bad...

[marshun]

voltmeter? would u test the ohms on it? idunno. i didnt even pick up a repair manual yet :P.

[MikeMurphy]

find something to plug into your OBD port....interesting stats so far

[MikeMurphy]

bump

[crazy2002mexican]

mine does it but i have 2 1/2 inch exhaust i just thought it was from not enough back pressure. Hey Aries what size tires/rims do u have?

[MainEvent212]

eh, i have an SR...i thought it was a joke lol so i voted for the power surge and backfire one...heh...i DO get a power surge...it's more like 3k rpm but still lol

[89240sx]

ok, I'll have to get the fsm first :-\

[PhaneSoul]

my power surge is 2nd gear 2500rpms to 6.5k

[MikeMurphy]

my power surge is 2nd gear 2500rpms to 6.5k

we call that your stock powerband...

[cory2081]

Ok, just some info on how a coolant temp sensor works. All it is is a varistor. As the temperature of the water in the engine heat up the sensor, the signal voltage to the ECU changes because of the increase in resistance in the sensor. Basically, the ECU sends a reference voltage, which is 5 volts on most domestics I don't know yet what Nissan uses, anyway, it sends this voltage to the sensor and what it gets back from the sensor depends on the temperature or resistance of the sensor. Very simple. It would be best to check with a scan tool so that you can see EXACTLY what temp the ECU sees, or, just go ahead and replace the thing if you think it may be bad. I'm sure that sensor isn't very expensive

[cory2081]

just curious, how many miles were on the car when you found this sensor was bad??