Knock sensor should be torqued to 14 ft/lbs...

I would try the upgraded ESC module first. It looks exactly the same as the stock one, unless you take it off and look at the part number on the back. Order if from GMpartsdirect.com, it's about $45 from them.

 

I found 65Z01's tech tip on using a newer ESC module, but not one on using a newer knock sensor...

 

Thanks, Mikey - I'm going to check the whole circuit first, and see if I find anything out of spec. At the point the parts-buying will probably begin...

 

To quote Ben Watson in his How to Tune and Modify Chevrolet Fuel Injection book for code 43 - "After confirming that the condition that caused the code to be generated still exists, check for 12c volts on the pink and black wire that is connected to the ESC module with the key on. Repair the wire or eplace the fuse as necessary. If the pink and black wire has 12 volts on it, turn the ignition switch off and connect an AC voltmeter to the white wire of terminal E on the ESC module. While closely watching the AC voltmeter, tap on the engine block with a 4 oz hammer. Does the voltmeter indicate any reading? If it does the knock sensor is good. If it does not, replace the knock sensor.

If the knock sensor tests positive, connect a digital logic probe to the ESC terminal of the ECM. If it reads digital low with the engine running, inspect the black wire from the ESC module to the ESC terminal of the ECM. If the wire is okay, replace the ESC module. If there is a digital high on the ESC terminal of the ECM, tap on the engine block. If the logic probe fails to latch for a digital low, then replace the ECM."

 

Basically what I intend to do, but I don't believe that I had that source - thanks!

 

That is explained so much better then the helms explains it...

I'm just lurking through this thread- but I'm gonna steal all your good ideas

and I should have explained myself a little better earlier- I meant if you start replacing things, and if you are looking for upgraded parts, I would buy an upgraded ESC, instead of an upgraded knock sensor (if thats even possible). But definitely let us know how your tests turn out.

 

So I get all my manuals and guides and printouts of this thread and head out to the garage...

...and the first thing it says in the manual is "elevate".

Sigh.

Bogus (at least) will be amused by the knowledge that John Porter is about to get (another) email.

 

yup. You ain't gonna fix the knock sensor from above. It just ain't gonna happen.

Say hi to JP for me!

 

But you can do everything to trouble shoot the ESC system from above. You only need to go below to confirm the wire connection at the sensor or remove it (the sensor).

RACE ON!!!

 

then there is that damned shield attached to the oil pan... gets on my last nerve!!!

 

I finally got around to following this testing procedure and never got past the first sentence. The voltmeter shows a tiny amount of voltage (.25 V) on the pink and black wire but nothing like 12 volts. So, the procedure says to replace the wire or the fuse. Before I go ahead and do that, I have some questions:

1) If the wire or fuse is bad, why am I getting any voltage at all?

2) If the wire of fuse is bad, why does the ESC eventually work?

Really, really, really confused.

 

Some more information:

1) Knock sensor has been replaced with a more modern one (1987 through 1989).

2) The end result of replacing the knock sensor is that the engine codes 43 more quickly, still with audible knock, but that knock is far less offensive (not as loud and doesn't last as long). After coding, the engine feels much more responsive and the check engine light goes out after 5 to 10 minutes. I then repeat this same process every time I start the engine...



3) Observation leads me to believe (though I am not sure) that the knocking is only happening in closed loop.

 

The code is set when the ECM receives less than 6 volts for 4 seconds or more from the ESC. When the ESC receives a signal, from the knock sensor, the 6-12 volt signal to the ECM is interrupted and the ECM retards the timing. It doesn't take 4 seconds of interrupted signal to retard the timing, only to cause the code to set. The point is, just because the engine knocks, and just because the timing is retarded because of that knock, doesn't necessarily cause a code to be set. Trouble codes set when a system malfunctions. Knock retard is not a malfunction. My interpretation of the code 43, is that the retard didn't happen soon enough or to a great enough extent to stop the knock. The codes are fault codes, not function codes.

RACE ON!!!

 

First, I'd like to thank you and the rest of C4 Tech for your patience. I still feel like I know so little...

Second, I think I've got it now as far as far as differentiating the timing retard signal (real quick) from the code 43 (takes four seconds). Assuming that the knock sensor/ECS was working correctly, what would cause it to be so slow to react, thus setting the code?

Third, is it possible that I'm measuring the voltage incorrectly? I set the car to run, disconnected the ECS module, and stuck the two voltmeter leads to complete the circuit (one on the pink and black lead and one on the spade that completes the circuit).

Finally, should I give in and take 'Lauren' to a professional?

 

You need someone with a laptop and a scan tool. I think that would help a lot.

 

I'm curious as to why it knocks. What have you done to try and solve that problem?