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knock sensor
- Thread starter Almeek69
- Start date
WobblesXJ
NAXJA Forum User
- Location
- South Carolina
That's a good question. I'd like to know this too. I guess I could unplug it and see.
MaXJohnson
NAXJA Forum User
- Location
- The Kansas Rockies
"good question" ???
what possible benefit would you expect from disconnecting the knock sensor?
As a guess, I would expect the system would throw a self-check code, but run ok as long as your octane is high enough to elimininate pinging.
what possible benefit would you expect from disconnecting the knock sensor?
As a guess, I would expect the system would throw a self-check code, but run ok as long as your octane is high enough to elimininate pinging.
- Location
- Terra Firma
It'll run, but it'll ping badly under load even when running high test fuel. All the knock sensor does is detect ping and retard the timing.
RobertF
NAXJA Forum User
- Location
- Santa Barbara
I have a 88 4.0 XJ (Renix) that came with a broken knock-sensor (outer cover pulls off steel thread body easily when you try to unplug them) used as a daily driver, it runs great on 87 octane with no pinging or over heating, thats not to say it won't run better with one, I just haven't put one on it yet.
I also have a 87 4.0 XJ (Renix) with such a worn out motor the timing chain slaps loudly at idle, and retards the timing. It runs much better with the knock sensor unpluged, but I have to run mid-grade in it or it pings. Got to rebuild it quick before it blows up.
They are both automatics, maybe one could lug a manual tranny harder and get more ping out of it with the sensor unpluged.
The Renix system has no check engine light, so how do you know if the knock sensor is even working if you don't hear it ping? I can see the timing change with a timing light on my slapping 87, sensor plugged and unplugged. I'll have to put a good sensor in my 88 and see if the timing retards when I smack the block with a hammer!
I also have a 87 4.0 XJ (Renix) with such a worn out motor the timing chain slaps loudly at idle, and retards the timing. It runs much better with the knock sensor unpluged, but I have to run mid-grade in it or it pings. Got to rebuild it quick before it blows up.
They are both automatics, maybe one could lug a manual tranny harder and get more ping out of it with the sensor unpluged.
The Renix system has no check engine light, so how do you know if the knock sensor is even working if you don't hear it ping? I can see the timing change with a timing light on my slapping 87, sensor plugged and unplugged. I'll have to put a good sensor in my 88 and see if the timing retards when I smack the block with a hammer!