I just put in my speed density 355 TPI motor (mods in sig). It was an 89 TPI motor that I converted to speed density. I keep getting code 43, even after reseting it. What are the possible things that could be wrong? I put in a brand new knock sensor, so it can't be that. What should I check? Is this hurting my performance? ANY help would be GREATLY appreciated. Oh yeah, I have a custom-burned PROM tuned for my cam. Thanks.

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1984 Camaro Sport Coupe - 73K Miles, Rebuilt 355 TPI L98, Crane 2032 CompuCam, Crane adjustible fuel pressure regulator, stock TPI intake, gutted air box with K&N filters
F41 Suspension Package, 700R4 Tranny, 3.27 Disc Brake Posi Rear
Hooker Shorty Headers, Catco High-Flow 3" Cat, Flowmaster 3" American Thunder Cat-Back
New Paint
Best 1/4 Mile Run (with old LG4 motor):
16.760 @ 80.74 MPH

Coming Soon:
Aluminum Drive Shaft

[This message has been edited by CamaroX84 (edited June 11, 2001).]

 

If code 43 appears after you drive it a few minutes, the ecm is probably not hearing the "knock test"...I had this problem with a new rebuilt engine..the knock sensor wasnt tight enough...
what the ecm does is it does a self knock test..it will deliberatly advance the timing to see if the knock sensor can hear the ping..if it fails this test it will set that code.The test usually happens before its just warmed up or when you first drive it.

If the sensor is new, and you dont have a scanner, youre going to be doing a trial and error test.
I had to screw my knock sensor all the way into the block before it worked right.
Even though the torque setting for it was really low..like 16 lbs or something.
Itjust couldnt hear the self test ping to make sure it was working properly.

Other factors are short in the wiring to the sensor.
Check the voltage at the sensor and the ecm (see what the manual says).

ALso if you used silicone on the threads of the sensor, its no longer "grounding" itself into the block.There cant be any silicone or sealent on it..you install it out of the box as is.

If you used sealent of any kind, clean it off and re install until it wont leak coolant.

Good Luck and I hope this was some help.

 

one other thing that is a real long shot is if you are using too high of octane fuel it may not be able to make it knock.

 

Thanks for the replies. Come to think of it, I did in fact put some sealant on my knock sensor. Guess I'll try taking it out (after I drain my coolant of course) and cleaning off the threads. Do you think this would almost definitely be the problem since almost everything is new? Also, does code 43 tell the ECM to retard the timing? If so, how much is this hurting my performance? Thanks for all the help guys.

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1984 Camaro Sport Coupe - 73K Miles, Rebuilt 355 TPI L98, Crane 2032 CompuCam, Crane adjustible fuel pressure regulator, stock TPI intake, gutted air box with K&N filters
F41 Suspension Package, 700R4 Tranny, 3.27 Disc Brake Posi Rear
Hooker Shorty Headers, Catco High-Flow 3" Cat, Flowmaster 3" American Thunder Cat-Back
New Paint
Best 1/4 Mile Run (with old LG4 motor):
16.760 @ 80.74 MPH

Coming Soon:
Aluminum Drive Shaft

 

The same thing happened to me last week. i had sealant on the threads so it couldnt ground itself. Drain the coolant and clean the threads and it should work perfectly. After i fixed mine i noticed a BIG improvement in performance and gas mileage. Good luck!

 

Also... you might have a fuel problem with the new program. You might be running lean, or have a bad injector or two. Too much timing...It might really be knocking, I was getting a code 43 and it turned out I had a few bad injectors. Just something else you might check. A scanner would really help, you could see what was going on. IM really happy with the Auto-x-ray I have.

Good luck!

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Black 90 IROC, L98, A4, 323 gear. SuperRamed 406 in the works!

 

If this code appears, then the car doesnt run strong, then yes its(ecm) going to pull out a tremendous amuont of timing.
Usually when the code appear and the car runs like crap or has no power, etc, its a sign that it failed the knock test.

Anytime the ecm sees this code, it "protects" the engine by runnng a fixed(LOW) amont of timing..so power and gas mileage will suffer for sure.

Let us know the update when you finish some work on it.

 

I looked it up last night because I'm about to install a resistor on my sensor wire.

GM's Service manual for the 86 Vette TPI engine specifically says that it's "IMPORTANT" (in bold type too) to wrap the threads of the sensor with tape.

I'm assuming that grounding the sensor via the threads is not an issue. It also says to use 14 lbs./ft of torque on the sensor.

Hope this helps,

Jake



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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9

 

Thanks for all the replies. It must have just been a bad connection somewhere. I pushed on all of them to make sure they were tight. One of them must not have been, because the car is fine now. I checked the conductivity of the knock sensor and it was fine, even with sealant on the threads. Ground was okay. I guess you just can't put globs of sealant on. Thanks for all of the help.