Knock Sensor - Need help
Thread Starter
Intermediate
Joined: Aug 2002
Posts: 28
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From: Cary nc
Knock Sensor - Need help
I just got a 1985 C4 and the check engine light stays on. I pulled the code and the Haynes manual says its a problem with the Knock Sensor. I'm not even sure where or what the knock sensor is or does, much less how to fix the problem. Please help.
Drifting
Joined: Aug 2000
Posts: 1,251
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Re: Knock Sensor - Need help (dacarlto)
What code is that?
The knock sensor hears noise & retarts the ignition.
Its located on the block low on drivers side.
Its purpose is to stop ping.Try higher octane ,check your timing.Reset computer. :chevy
The knock sensor hears noise & retarts the ignition.
Its located on the block low on drivers side.
Its purpose is to stop ping.Try higher octane ,check your timing.Reset computer. :chevy
Instructor
Joined: Sep 2002
Posts: 136
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From: Port Moody BC
Re: Knock Sensor - Need help (nobodyunknown)
What's with this code 43 Knock Sensor problem on a lot of 85's??? I have the same problem. The code pops up under heavy excelleration when the car temp is around 200 degrees. I know that the sensor does a check on startup and around 200 degrees. I have replaced the knock sensor, the Electronic Spark Control and checked the harness wires to the computer. Use 92 octane Chevron gas.
Seems no one has any idea how to fix this problem. Could it be the ignition module??? What else could be causing this problem?? Any new ideas to check that haven't been mentioned in previous posts??? Getting a little frustrated with this problem and realizing that I am not the only one!!!
Gary :mad
Seems no one has any idea how to fix this problem. Could it be the ignition module??? What else could be causing this problem?? Any new ideas to check that haven't been mentioned in previous posts??? Getting a little frustrated with this problem and realizing that I am not the only one!!!
Gary :mad
Melting Slicks
Joined: Apr 2002
Posts: 3,019
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From: down that one road next to that big tree
Re: Knock Sensor - Need help (drvette85)
replace the knock sensor & run higher octane gas, try 98 oct or a can of octane booster at least. also check your base timing, with the thing unplugged you should be at 4-6deg before top dead center. this should fix it, after that take burns out see if it comes back without the octane booster, it probably won't.
Drifting
Joined: Aug 2000
Posts: 1,251
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Re: Knock Sensor - Need help (drvette85)
Did you guys know that loud exhaust will activate the knock sensor?
Its true,the solution there is a knock sensor from a LT4.
Also If you run to high of an octane,then at start up the computer does the test and cant find the ping in its normal range thus allowing the timing to advance to far.It sounds stupid but go back to the 87 octane that is recommended by Chevy. :chevy
Its true,the solution there is a knock sensor from a LT4.
Also If you run to high of an octane,then at start up the computer does the test and cant find the ping in its normal range thus allowing the timing to advance to far.It sounds stupid but go back to the 87 octane that is recommended by Chevy. :chevy
Drifting
Joined: Feb 2000
Posts: 1,994
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From: Charleston, WV
Re: Knock Sensor - Need help (nobodyunknown)
Guys I learned this from Beach Bum, then I looked in my fuel injection manual and it was right there. This is the deal....... when the engine get's to 194 deg the puter looks for a signal from the KS. If it's not there you get that code. then you get the light. Turn off the car and restart and it will run fine again. I can go deeper into it if you want .......let me know but I run my KS unhooked and I have a 160 stat so I don't get that code anymore
:seeya
:seeya
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Melting Slicks
Joined: Apr 2002
Posts: 3,019
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From: down that one road next to that big tree
Re: Knock Sensor - Need help (Ron78Z&85Vette)
odd i remember placing one in a waterjacket in my shortblock, it's a stock part....you sure about that ron :rolleyes:
Burning Brakes
Joined: Apr 2002
Posts: 755
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From: Patterson CA
Re: Knock Sensor - Need help (Ron78Z&85Vette)
GM part number for a knock sensor (84-86) is: 1045-6287, if you need it.
$49 dealer / $25 http://www.gmpartsdirect.com :yesnod:
Also, someone once told me that if the wire that connects to the knock sensor is touching or to close to a spark plug wire you can pickup false knock readings.
[Modified by VetBoy89, 1:21 PM 9/26/2002]
$49 dealer / $25 http://www.gmpartsdirect.com :yesnod:
Also, someone once told me that if the wire that connects to the knock sensor is touching or to close to a spark plug wire you can pickup false knock readings.
[Modified by VetBoy89, 1:21 PM 9/26/2002]
Drifting
Joined: Aug 2002
Posts: 1,451
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From: Calgary AB
Re: Knock Sensor - Need help (gtsyellow)
odd i remember placing one in a waterjacket in my shortblock, it's a stock part....you sure about that ron :rolleyes:
Team Owner
Joined: Dec 2000
Posts: 90,675
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From: SE NY
Cruise-In II Veteran
Re: Knock Sensor - Need help (dacarlto)
It could be a problem with the knock sensor or the ESC module which is part of the circuit on early L98s.
The knock sensor is located in the lower right rear of the block near the starter.
The ESC module is located near on the outer right side parallel with the side panel near the firewall.
[Modified by 65Z01, 4:51 PM 9/26/2002]
The knock sensor is located in the lower right rear of the block near the starter.
The ESC module is located near on the outer right side parallel with the side panel near the firewall.
[Modified by 65Z01, 4:51 PM 9/26/2002]
