Hey guys trying to diagnose a problem I'm having. Traced it down to the knock sensor and found out I'm not getting volts with Key On Engine Off like I'm supposed to. I get 100k ohms when I test the sensor. I've tried a few ESC's and also tried to replicated knocks using Tuner Pro RT and got nothing. What could be going on?

 

When you say your not getting the proper voltage are you checking the ignition 12v and the ground on the esc pin B and D or the output 5v on E ?
btw are you getting excessive false knock or code 43 ?

 

I checked both. I get the 12v on the B and D. I'm not getting the 5V on E. I'm also not getting error code 43. The wire for the knock sensor, is it Blue or White?

 

the blue wire is for the knock sensor on pin e of the esc. It could be white or even grey I'm not sure the color used on 87.

 

I'm doing this testing according to my 87 FSM which says the knock sensor wire is white. The blue wire is going to the temp sender in the head. However I just read a thread with quite a bit of posts and it was said for a 87 Camaro 5.7 TPI the knock sensor wire was blue.
If I test the blue wire and it gives me voltage for the knock sensor with KOEO then is it safe to say that's for the knock sensor?

 

Just checked. The blue wire gives me 11.8 volts with KOEO

 

I can't remember the output of the esc I thought 5v but it could be 12v. If that wire is hooked to the temp sender in the head between cyl 6 & 8 and a grey wire is going to the drain hole in the block the two connecters are switched. If you ground the grey wire with the connector like the is koeo the secondary fan will come on.

 

So the blue wire that I just pulled from the temp sender between cyl 6 & 8 should in fact be going to the knock sensor?

 

Should be you can plug it on the ks and unplug the esc connecter and would have 100k measuring the resistance from the esc connecter pin e to ground to verify that is the wire.

 

I really appreciate the quick response and help so far. I guess it's safe to say the KS wire color for my car is the white wire. I checked resistance with the blue wire connected to the KS and probing pin E and ground, got nothing. Plugged white wire in and checked resistance and got the 100k you mentioned. This is the digital dash if that makes any difference. Should I not be seeing volts on the KS wire?

 

I believe the tpi maf esc works similar to the knock filter on 90-92 speed density. koeo there is voltage to the ks.

 

I just did the knock test on PIN E and resistance on the volt meter responded with the knocks.

 

That terminal B7 is different from mine. On my ECM B7 is for the EST which gives 9.5v, which is what I got when I back probed it. This is weird though. I get the resistance on the KS when I probe pin E on the ESC harness. As soon as I plug the ESC in, that 100k turns into 02.0. What does that mean?

 

B7 on a 1227165 ecm is esc retard wich should have 9v .
Don't measure resistance with power going through the wire or or you might find magic smoke in your vom.

 

That's what I was getting. Is 9.5v over doing it?

 

you might see 9.3-9.5, I don't understand what your main issue is False KR ?

 

Yes. It doesn't seem like the computer is receiving the knock counts

 

You will see a few knock counts and a force knock test will increase the number aswell. If your having a real knock issue power will be down and timing will retard or low blm .

 

Well I just discovered that my balancer has slipped and the timing mark is complete opposite of the keyway. So gotta get that fixed

 

Sounds like you're in good hands here. I just wanted to chime in and say I've seen the KS and temp sender wires reversed on quite a few of these cars- both wires have enough length to plug them into the opposite sensor and they are the same style connector. If the plugs on them are original (and not long since mangled and destroyed) they are actually color-coded to the sender they belong with. One's dark, one's light colored (who can say exactly what color they really are after all the years, mileage and road-crud! That's why I just refer to them as light & dark). Anyway, That's the sensor it belongs to.

 

I know this is an old thread, but ran across the same issue with my '88 TPI. After carefully checking the factory service manual, I discovered the knock sensor wire runs directly to terminal "E" on the ESC module. In my case, it turned out the wire color for terminal "E" was white. Using a DVM, I was able to confirm that the WHITE wire was in fact the knock sensor wire, and the blue wire was for the fan switch on the passenger side head.

As far as the color of the terminal at the sensors themselves, on my '88, the white connector went to the knock sensor, and the black connector went to the thermal switch on the passenger side head, between the #6 and #8 spark plugs.

In short, the easiest way I found to confirm which wire was which was to disconnect the terminal block from the ESC, then use the continuity check on my DVM from terminal "E" on the ESC connector to the knock sensor connector itself confirm which wire belonged to the knock sensor.