Code 43 woes....need help!
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Joined: Sep 2001
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From: Baytown Texas
Code 43 woes....need help!
Ya'll,
Need help with my '85. I still get detonation for a few seconds, then a code 43, after I apply WOT past 193 degrees on the temp. guage. I'll also get it in 4th gear at low rpm's (high load) after it's reached the same temperature.
According to the book, it's failing the knock sensor test that occurs once per startup and when the temperature is past 193 degrees. The ECM advances timing, and receiving no input from the sensor, sets the code 43.
I've replaced the knock sensor, ESC module, and EST module within the distributor....all with AC Delco parts. My static timing is set at 9 BTDC...up from the recommended 6BTDC.
Nothing else is amiss, and she runs like sin below the 193 degrees. Why is it failing the "test", unless it's the ECM itself? Anyone else conquered this problem? Thanks in advance!
Need help with my '85. I still get detonation for a few seconds, then a code 43, after I apply WOT past 193 degrees on the temp. guage. I'll also get it in 4th gear at low rpm's (high load) after it's reached the same temperature.
According to the book, it's failing the knock sensor test that occurs once per startup and when the temperature is past 193 degrees. The ECM advances timing, and receiving no input from the sensor, sets the code 43.
I've replaced the knock sensor, ESC module, and EST module within the distributor....all with AC Delco parts. My static timing is set at 9 BTDC...up from the recommended 6BTDC.
Nothing else is amiss, and she runs like sin below the 193 degrees. Why is it failing the "test", unless it's the ECM itself? Anyone else conquered this problem? Thanks in advance!
Drifting
Joined: Aug 2000
Posts: 1,251
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Re: Code 43 woes....need help! (Red85)
Have you changed the temp sensor on the front of the right head?
Mine misses till about 125 degrees then runs fine.
Im thinking knock sensor or ESC on mine.
I also think it might just be when its in open loop.
Good luck.
Mine misses till about 125 degrees then runs fine.
Im thinking knock sensor or ESC on mine.
I also think it might just be when its in open loop.
Good luck.
Race Director
Joined: Aug 2000
Posts: 14,130
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Cruise-In II Veteran
Re: Code 43 woes....need help! (Red85)
I had this problem and David F helped me solve it.
It seems that your car is failing the ecm knock test,so it will run crappy because the ecm is trying to keep your car from exploding or so it thinks.
What I did wrong was I put silicone around the knock sensor.The knock sensor couldnt ground so the ecm couldnt hear knock.
If you added any sealant to the sensor, take it off.The knock sensor needs to be able to ground.
also,Whats the torque setting did you install the sensor?
The factory setting for mine was too weak.I basically screwed the sensor into the block until the ecm could hear it knock.Didnt even bother torquing it to specs.
Lucky for me, this didnt make it over sensitive and retard timing over some other false noises from the engine and etc.
It seems that your car is failing the ecm knock test,so it will run crappy because the ecm is trying to keep your car from exploding or so it thinks.
What I did wrong was I put silicone around the knock sensor.The knock sensor couldnt ground so the ecm couldnt hear knock.
If you added any sealant to the sensor, take it off.The knock sensor needs to be able to ground.
also,Whats the torque setting did you install the sensor?
The factory setting for mine was too weak.I basically screwed the sensor into the block until the ecm could hear it knock.Didnt even bother torquing it to specs.
Lucky for me, this didnt make it over sensitive and retard timing over some other false noises from the engine and etc.
Racer
Joined: Apr 2001
Posts: 322
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From: Sherburne,NY NewYork
Re: Code 43 woes....need help! (Red85)
I would suggest using the correct GM knock sensor,do not apply anything to the threads and torque to the correct specification,which is 15-17 lbs/ft. If you do this you should not have a problem. If you still set a code 43,follow the diagnostic chart in the GM shop manual to the letter.
Vette Punk :conehead
Vette Punk :conehead
Racer
Joined: Apr 2001
Posts: 322
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From: Sherburne,NY NewYork
Re: Code 43 woes....need help! (Red85)
Just remembered one more item that I have seen more times than I care to think about.Check the blue wire going to the knock sensor,be sure that it is not pinched anywhere. Look especially close at the area around the starter. Often what happens is during a starter change the wire gets trapped between the starter and the engine block.
Vette Punk :conehead
Vette Punk :conehead
Drifting
Joined: Apr 1999
Posts: 1,261
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From: Middletown New Jersey
Re: Code 43 woes....need help! (vette punk)
I had a similar problem till I changed the ESC module to a different part number as recommended by 65Z01. Unfortunately I don't have the part number but I did purchase it thru Jeff Kopp. Do a search of ESC module using 65z01 and you will find the proper part number. Maybe Jim (65Z01) will chime in here.
Hope it helps.
Hope it helps.
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Joined: Sep 2001
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From: Baytown Texas
Re: Code 43 woes....need help! (GlennS87)
Thanks, ya'll....
I'll do the book tests, but have been reluctant to do so due to the mention of a digital logic probe. I don't have one and would need to be schooled on it.
I didn't use sealer on the threads of either sensor I installed, but confess I didn't use a torque spec when I installed it.
I'll do the book tests, but have been reluctant to do so due to the mention of a digital logic probe. I don't have one and would need to be schooled on it.
I didn't use sealer on the threads of either sensor I installed, but confess I didn't use a torque spec when I installed it.
