KA24DE Knock Sensor Troubleshooting

[Ilya]

CAR: S13 Convertible converted to 5 Speed

SYMPTOMS/DIAGNOSIS:

I read a bad knock sensor can retard timing by upto 12 degrees. I did general maintenance on a 22 year old car that was way over due:
-New Coolant Temp Sensor
-New injector #4 and all O-Rings (no they are not leaking)
-New Tomei FPR with gauge set to 36PSI w/ Vacuum 43 W/O. Pressure holds when fuel pump is primed aka no fuel leaks into cylinder. Cylinder Tops are dry.
-New NGK Irridium Sparkplugs
-Clean IACV
-All new Vacuum Hoses
-New Thermostat and New Coolant
-Timing is set correctly using Nissan Consult

My car still is getting around 290MPG. Often times when I come up to a stop I get a whiff of rich exhaust like a diesel, and coming to a stop, the idle drops to about 400rpms and goes back up to 700rpm when speed hits 0MPH.

I have a Nissan Consult and have data logged some test drives. What I found is that when I am coming to a stop, my timing gets retarded by 12 degrees from 20 to 8.

Data Point 1

http://i78.photobucket.com/albums/j81/ilya_2006/LogScreenShot1.jpg (http://s78.photobucket.com/user/ilya_2006/media/LogScreenShot1.jpg.html)

Data Point 2
http://i78.photobucket.com/albums/j81/ilya_2006/LogScreenShot2.jpg (http://s78.photobucket.com/user/ilya_2006/media/LogScreenShot2.jpg.html)

As you can see ALL functions are working properly, TPS, MAF, O2. Im not to savy yet with how timing is controlled through out Loads/Acceleration/Deceleration. Hopefully we can make this thread educational as I can get more data points of what you guys would like to see.






My question is:

Is timing retardation expected as shown in the Data Log when coming do a stop (im downshifting in the log)?

[Ilya]

http://i78.photobucket.com/albums/j81/ilya_2006/logpart3.jpg (http://s78.photobucket.com/user/ilya_2006/media/logpart3.jpg.html)

The engine runs great, no knock sound, but from the graph it looks like the ECU is retarding timing during light acceleration for no reason...sound like a bad knock sensor? Any insight?

[OnTheChip]

Timing is retarded 15º in overrun with throttle closed, which is normal.

[Ilya]

How can I test the knock sensor via logging?

[UNISA JECS]

How can I test the knock sensor via logging?

You compare you "timing map" values against your "logged" values and if they don't match up that is where the ECU is pulling timing out.

*
Observation if this is a M/T car you need to adjust your TPS sensor .42v is to low need to be between .45 - .55v for closed throttle IIRC on the KA24DE and yo might as well set base timing/idle while your at it.

[Ilya]

TPS = 0.5V +-0.02 I'll fix it up and report back with the results.
Correct me if I'm wrong, but timing map cannot be viewed for a factory ecu?

Thank you for the reply

[Ilya]

Does anyone have the addresses for a ka24de ECU timing maps?

[Ilya]

-Tps = 0.5v at idle
-Oxygen sensor fluctuates between high and low voltage about 8 times every 10 seconds per the fsm. And it's new
-MAF voltage reads a few milivolts low at idle 0.8-1.0v
-timing is set to 20 using a timing light per FSM and the nissan data scan timing set feature. Once set and locked, timing idles at about 12 degrees.
-spark plugs are new ngk irridium
-no vacuum leaks as I replaced all the hoses in the back of the engine
-power balance test I'll have to get the values for later today
-sudden drop in MPG after replacing injector 4 and all the large orings that the fuel rail seats into; no leaks.
-no gas smells but an occasional rich smell
-about 280mpg where before it was about 330

Not sure what is going on, I have data for everything. Any ideas would be great. Possibly knock sensor since timing is pulled so much at idle?

[Ilya]

Replaced cap and rotor, no change

Cleaned IACV, no change

Replaced FPR, no change

Replaced oxygen sensor, no change

Replaced all injectors, one had a messed up pintle cap. That was the issue. Getting 400 miles to the tank

[andisan]

All that because of the pintle cap? Does that really affect it that much? I'm curious can someone explain, thanks

[Ilya]

Something must have happened that was traumatic enough to break a pintle cap. So it's not the broken cap that is the issue but what caused it. A few months before this, I had another injector go out. So something must have propagated into the system.

[bad dog]

i have a 97 , pretty much stock except for cai , greddy cb , under drive crank pulley .

i got tired of changing the knock sen , i cut the wires and put a 440,000 ohm resistor across the wires going to the ecm, now it thinks the ks is good . another thing that would set your timing lower would be a bad cold air intake sensor , if it shows air is too hot it will retard the timing and also give the engine less fuel .

you may not want to use the resistor if you have a turbo with lots of boast .