Knock Sensor Module(ESC) used with Megasquirt

[TurboProject]

I currently am running my 3.4L V6 on a megasquirt controlling fuel and spark amung other things.

I originally set up a knock sensing scheme using this circuit for the megasquirt:

http://megasquirt.sourceforge.net/extra/knock.html

I would get false knock signals all the time so I just disabled it. I attributed a lot of the false signals to the over-sensitive circuit that wasn't really based on the frequency expected out of the 3.4 when knock is occuring.

Next, I saw this article on the megasquirt site about using a knock module(ESC) from a mid 80's to early 90's GM vehicle. I think a lot of the V8 f-bodies and corvettes used them. It was mounted externally to the PCM. Here is the writeup:

http://www.megamanual.com/ms2/knock.htm

Seeing that gave me the idea of trying to use the removable knock module that is mounted inside my PCM under the little cover. The only problem is that I had no idea what the pin-out on the connector was or if it can even be used in the same way as that megasquirt writeup. I took my PCM apart and tried to map out where the traces were going on the boards in the PCM from the knock module connector. I think I was able to map it all out. I've made up a little diagram for what I think I found.

Does anyone know enough about these modules to verify this? I seemed to be able to trace all of the resistances I was reading to actual physical resistors on the board. The 100ohm resistor was a little surface mount guy and the 110ohm one was a large power resistor that looked like it fed a bunch of other electronics coming directly from the +12 input for the entire PCM.

Let me know what you think. I'd like to try and connect the knock module in my PCM to the megasquirt to get a more acurate knock sensing set up since the module should be tuned for my engine and knock sensor.

[ForcedFirebird]

I'd like to know how you make out on this, I am going to use the KS and MS1 w/spark for the new motor.

I can contribute that different models carried different sensitivity on the sensors. People who are afraid their roller rockers will trigger the KS retard, and switch to a different sensor (In LSx's). The KS is extremely sensitive in newer motors.

[TurboProject]

Am I going have to be the first person that tries it? I could just get a module, wire it up like the diagram and look at the output on a scope.

I would prefer to find a cheap knock module somewhere to test with though in case I burn it up.

[ForcedFirebird]

JY. A lot of times they will let you have this kind of stuff for $5-10.

[TurboProject]

Good point. I guess I could get one and assume it works the same as the one in my car(not sensitivity, just connectivity). But I would want to use one for my exact car if it works to run with the megasquirt.

[ForcedFirebird]

Are you a member at the MS Forums?

[TurboProject]

Yes, TurboCamaro is my name on there. I haven't posted much in a while.

Maybe I should post over there about this...

[ForcedFirebird]

Yes, TurboCamaro is my name on there. I haven't posted much in a while.

Maybe I should post over there about this...

I've been seeing you around lately. The only place I am not Forced Firebird is Thirdgen.org, there I am firstfirebird.

What happened to trying to mod the OBD 1.5? I think it's better to go with MS. I will be using MS1 with spark and knock. I had a built unit, but when I detonated my motor, sold it to use the money to pay for a new block (and upgraded to 3.4). This time I am going to build it myself, KingEFI left out a capacitor the first time I got one. That and they are on sale for $135, the only snag is I have to convert to PWM IAC, rather than a stepper IAC (MS1 doesn't support steppers).

[94Camaro]

glenns garage has a kit (build it yourself) to add stepper motor control to the megasquirt...just fyi.

[ForcedFirebird]

glenns garage has a kit (build it yourself) to add stepper motor control to the megasquirt...just fyi.

MS2 supprots it with the v3.0 I didn't think there was a way to use a stepper with MS1. I aksed at their forums.

BTW Russel, have you seen the progress on the 3500 heads? What did you do for brakets on your top swap? Sorry to pirate .

[94Camaro]

MS2 supprots it with the v3.0 I didn't think there was a way to use a stepper with MS1. I aksed at their forums.

BTW Russel, have you seen the progress on the 3500 heads? What did you do for brakets on your top swap? Sorry to pirate .

havent really been following anything about anything.

my car runs in its current state and im not ready to do anymore upgrades or anything so it doesnt really matter. i dont plan on following anyones ideas when i do get back on the mod wagon.

also - i tend to stay away from stupid sites like fullthrottlev6 because of the idiots on there (not everyone is, just the moderators (most) and owners) that preach their own gospel even if its not true, and shut out anyone who speaks against what they know.

as for brackets - you mean accessory brackets? i just used the stock ones that came with the car:

check out my pics: http://www.adwire.com/camaro/modpics/

its all in there.

[ForcedFirebird]

havent really been following anything about anything.

my car runs in its current state and im not ready to do anymore upgrades or anything so it doesnt really matter. i dont plan on following anyones ideas when i do get back on the mod wagon.

also - i tend to stay away from stupid sites like fullthrottlev6 because of the idiots on there (not everyone is, just the moderators (most) and owners) that preach their own gospel even if its not true, and shut out anyone who speaks against what they know.

as for brackets - you mean accessory brackets? i just used the stock ones that came with the car:

check out my pics: http://www.adwire.com/camaro/modpics/

its all in there.

The bolt holes are different from the iron to the 3400, and 3400 to 3500 heads. You mean you used the stock 3.4 brackets and modified them, or did they fit?

Here's where I'm at, test fitting the heads on the 3.1 block to mock up headers and such...
http://s158.photobucket.com/albums/t...ybrid%20Build/

[TurboProject]

I still want to try and play around with modding the obd "1.5" PCM. But it's more of a side project...try and help out the community, etc.

I've been running megasquirt since 2004. My current setup is running a megasquirt-I w/ a v2.2 board and MSnS-Extra code. I'm controlling fuel, ignition, cooling fans, and a/f ratio targeting using a wideband sensor(LC-1).

I don't have any idle air control. I just opened up the throttle plates a little in my adapted LT1 throttle body to have it idle well in most conditions. It still likes to die when it's cold with the a/c on if I'm not careful on starting from a stop. I was planning on running PWM idle control but didn't want to add more hoses, etc to it.

glenns garage has a kit (build it yourself) to add stepper motor control to the megasquirt...just fyi.

Is this what you're talking about Russle?

http://www.glensgarage.com/catalog/wire-idle-valve-driver-board-p-79.html

I don't think that's for the GM stepper motor idle control valve. It says for 3-wire ones and the GM ones have 4 wires.

[ForcedFirebird]

94 Camaro is Russel, and he was the first to do a 3x00 top end swap in an f-body (as far as I know).

No to my knowledge MS1 will not support a 4 wire stepper. You can adapt a Ford TB, though, and from what I understand, most have PWM. You can also adapt an EGR valve to work (but you may have already looked into this).