Knock module for MS3

[Matt Cramer]

And they're ready to order:

http://www.diyautotune.com/catalog/ms3- ... p-522.html

[bcrx7]

That's awesome Matt! Great you guys released this even with all the work happening in the salt flats!! Cheers

[savagerocco]

Thanks Matt, got mine and the RTC coming as well. This probably would have saved me a piston if it had been out a few months ago. Crappy E85 that turns out to only be E55 and probably mixed with low grade gas did me in.....

[UnaClocker]

I noticed the same thing about E85 the last time I was running it. Big fat label on the pump clearly says MINIMUM 70% ethanol. I emailed everyone I could think of that might care, regulators, ethanol coalition, etc.. Nobody even emailed back. E85 is out of style, and on it's way out of existance, sadly.
Good to see this knock module tested well and is out. If the Chrysler 2.2/2.5 decoder ever gets fixed (I'm sure it will, someday), I'll be happy to have knock sensing.

[Dookie454]

I got my Knock module for my MS3X today yeay! I just installed it by soldering to the MS3 board, now I'm looking for free pins to use existing unused wires on my DIY harness rather than trying to use the DB15 port.

So according the the MS3X wiring diagram, it's full.

How about the MS3 wiring diagram... Pins 3-6, pin 3 is labeled as 1/Can H and pin 4 as 2/Can L... but then there's PIN 5-6... they say "Spare Pins" labeled 3-4 on my wiring diagram (but they are real pins 5-6)...

Could I use these two inputs for Knock sensor 1 and 2? Does the DIY MS3 wiring harness have wires populated for these pins? (Pins 5-6 on the MS3 output).

[jsmcortina]

As you say, pins 5 & 6 on the mainboard plug will often be free. These are SPR3+4 on the mainboard.

James

[Dookie454]

thanks.. I wired it like this.. the DIY harness has the wires so I should be all set.. now is there a way to test the knock sensor out of the engine.. on the bench... using the jimstim for RPM? directions mentioned the tuning frequency should match the engine that it came out of however I'd like to simply see if I get something by tapping the knock sensor with something (out of the block... sitting on the bench).

Since my MS3X is already installed and running my 1997 Vortec 350ci Truck, all I have to do is splice into the factory wiring for the signal hopefully this will piggyback ok.. and want to make sure my install is working before I do that.

[jsmcortina]

As the sensor interface is tuned to a frequency you might not get much response off the engine. Lightly tapping the block with it installed and engine running might give you something.

I tested mine running the car on stands while standing on the brakes and throttle. 1000rpm and high load showed I had too much timing in the table there.

James

[Dookie454]

that's what I figured... but for now I think I have another problem as I'm getting knock detection with and without the knock sensor connected.. at first it was random and varied with Jimsim RPM.. but then I opened up the knock detection windows to the max (-50 start and 50 end) and it appears to be constantly knocking at say 2500rpm.. if I slow it down to 250rpm.. the knock indicator blinks slowly.. between 1-2x a second...

I adjusted the frequency from stock 4.95 to the lowest and this still acts the same way.

My msq is attached. I should not be getting knock with no sensor connected, should I? If I connect the sensor.. I get the same thing.

I soldered all pins of the knock module to the board.. it didn't mention soldering the back two supporting pins to anything but I assumed I should solder them to the pins they lined up with.. so I did after checking that the two pins appeared to not connect to anything.

Edit: I played with it some more.. no tune changes.. but now the knock is either ON or OFF depending if I turn RPM to 0 (as if I were to stop engine). Restarting either turns knock ON or OFF.. and it seems to stay either ON or OFF randomly, until the next time I "restart" using the Jimstim RPM.

Edit 2: I updated to MS3 Release 1.1.2 and I still get a random KNOCK always on when "staring" using the jimstim.. Once started the KNOCK is on until I shut off, and KNOCK will stay on until I randomly restart RPM with Jimstim.. and keep getting random solid KNOCK

[Dookie454]

As I posted before, I'm getting almost random "Knock Input" when RPM is turned higher than 0, each time the simulated engine is started.. Knock Input % jumps to a random number and holds until RPM = 0. Also I tried to turn on the fidle LED on the jimstim and link it to "KNOCK" but the two indicators dont follow each other (fidle is always on when RPM is showing) and the default "KNOCK" indicator on the TS dash comes and goes but is solid as I cycle RPM from running to 0rpm. This is with or without the knock sensor connected, everything else setup like the directions say.. running TS v2.0.5d and MS3 release 1.1.2.

with RPM greater than 0, whatever initial value the Knock Input % jumped too.. it holds, no matter what I do (jiggling sensor, disconnecting sensor wires, grounding them, etc. the KNock Input % holds steady until RPM is put back to 0.

How it's suppose to work? Is this normal when using the JimStim?

What gauge is suppose to show knock occurring cause right now it looks like it's just picking a random number when RPM goes from 0, to run.

Knock retard gauge always shows 0.

I'll try it on a real engine tomorrow.. but I figured the Knock Input would at least be consistent? Or does it need engine noise to generate voltage to start working?

[savagerocco]

Well, I got my knock module and RTC module installed. I had the IAC pads open, so I will be running those for the knock sensors.

[chips60bug]

Same here!

[Dookie454]

K I answered my own questions... when connected to a running engine I get Knock Input signal moving around with engine speed.. so I guess it's working.. just need to figure out what settings detect knock!

Edit: NO bandpass settings detect knock. My Knock Input reads around 40% fluctuating ~5% I have a switch swapping the stock ECU and the MS3 ecu.. I put allot of advance in with the MS3 ECU and flip the switch between the two ECU's to test for knock which I can hear.. but the MS3 doesn't detect anything, the Knock Input never moves outside of it's no knock range. I tried many of the different Bandpass Frequencies including 4.95khz which calculated from my 4" bore.. and nothing, yet I can hear knock.

Its a 1997 Chevy v8 sbc 350ci, iron block and heads. It looks like an oil pressure type resonant? knock sensor.

I wired the two KS inputs to the spare pins 3+4 on the MS3 harness, however I did not use the grounds on the old DB47 or what was shown in the install diagram.. do I need those to go to engine ground, I assumed the rest of the MS3 grounds on the engine would be fine.

How do I know the sensor is working cause my KNock INput signal is moving around with RPM like there's noise.. just not detecting knock. Another problem I have is when my electric fan comes on my Knock Input shifts 20-30%, but my main concern is the system is not picking up any knock at all.. but I can hear it.

[BCM]

It looks like an oil pressure type resonant? knock sensor.

That might be your problem, unless it is designed for an engine with the same sized bore. You might want to try a "donut" shaped wideband sensor, and set the bandpass frequency based on your bore size...

[Dookie454]

It looks like an oil pressure type resonant? knock sensor.

That might be your problem, unless it is designed for an engine with the same sized bore. You might want to try a "donut" shaped wideband sensor, and set the bandpass frequency based on your bore size...

the sensor is stock from GM for that motor. it still works with the stock ECU.. but I will try the other style sensor, thanks!

[jsmcortina]

It would be a great shame if the stock sensor doesn't work correctly, however, a single wire sensor is never going to be great due to earth looping issues.

I've yet to try the stock sensors on my LS motor.

James

[BCM]

Just a guess here, but is it possible the stock sensor is filtering out one range of frequencies, and the knock chip a different range, thus in reality filtering out everything and detecting no knock?

This would need to be tested, but with a stock resonant sensor like that, the knock chip filtering might not be needed?

[Peter Florance]

It would be a great shame if the stock sensor doesn't work correctly, however, a single wire sensor is never going to be great due to earth looping issues.

I've yet to try the stock sensors on my LS motor.

James

Will you post here if you do?

Thanks

[jsmcortina]

Sure... but the car presently has no back axle or rear-suspension so even testing on axle-stands is months away.

James

[Dookie454]

I ordered BOSCH - 0261231036 due to the long built in wire.. but now noticed it's 3 wires.. hopefully this will work?

http://www.ebay.com/itm/130728939188