MS3 and LT1 Camaro

Testing and development of Megasquirt 3

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shortbus
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MS3 and LT1 Camaro

Post by shortbus »

I am close to getting my MS3 +1996 LT1 Camaro project off the ground.

I have the MS3 built and bench tested. I have to build the connection for the factory harness. Which brings me to my first question:

Does anyone have a pin out of what pin out diagram from the factory harness to the MS3 harness?

I have started one for my self and most of it is self explanatory, but I do have some specific questions like:
Does the Crankshaft Position Sensor go to Pin 8 on the MS3?
How did you plug in your fan controllers? One to Fiddle Pin 30? and a user built circuit in the proto area?
What knock snesor did you use?
What in on the MS3 did you connect to the knock sensor?
(Yes, I know about the knock module and I saw MSKnocksensor but they did not return emails, and I bought and 89 vette module to use)

Those are my initial questions....


Here is my car and plan.

1996 Camaro LT1
Bored 30 over.
11.9:1 compression
58 mm tb
Delteq ignition and GM DIS 8 ciols from a Northstar motor


Stage one is to plug in the MS3 and let the delteq do its thing with the coils because it is transparent to the computer.

Stage two will be to either move the current ignition wires from the opti to the MS3...
OR go to coil per plug. I have not decided.

I have not found all the information I need as of yet to control the DIS 8 pack with the MS. But that can come later.

Any helpful comments will be appreciated.
atomic6
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Re: MS3 and LT1 Camaro

Post by atomic6 »

The Delteq may make it a little wierd, I'll look into that.

With the MS3 I don't think the cranksensor is needed, or even has an input on the ms3. That is the way I think James is going to go about it(full opti-wheel decoding)

The original OBII computer for the LT1 only used the crank sensor for the misfire detection I believe.

I think the ms3 will be a great match to the LT1 but, I don't anyone is using it, or has even tried yet.

I will evenually look at using it on my LT1 RX-7. But probably not until the MS3x hits the shelves.

On the fans, if they are the factory two speed fans, I always hook the low speed(neg. trigger) to the fuel pump output, and then assign an output for kicking it on high. And at WOT they kick back down to low if they were already on high. For less electrical load when going down the dragstrip. that is just how I do all the cars that we have that use a series two speed fan like the LT1/LS1 use.

If you need it, I can try to help, I am Familiar with the LT1 and the variants.
1986 G.N. (sold)
1967 Nova II wagon (sold)
ex-MSer
shortbus
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Re: MS3 and LT1 Camaro

Post by shortbus »

Thanks a bunch. I am sure I'll need help.

The delteq is actually completely transparent to the stock ECM.... And i *believe* it will be transparent to the ms3 too. Until I use the ms3 to control the GM dis 8 module. But, I might go straight to ls coils instead. The delteq is just translating the gin signal post ecu.

So I need to add the 2nd fan control cirtuit in the pro to area?
atomic6
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Re: MS3 and LT1 Camaro

Post by atomic6 »

The Delteq doesn't have a "timing map" in it, as you said it decodes the opti high and low res. signals into the cam and crank signals the Northstar module is looking for.

So without an est. signal from the factory computer the delteq will run the LT1 but it will be locked at the 10 degrees the northstar module fires the coils at.

Until it sees a bypass signal, and EST signal from the factory computer, or maybe the MS3. But the Opti high res. and low res still go to the factory camaro computer to decode it also, then the factory computer generates the est signal it normally sends to the factory coil module on the pass. side head but now the Delteq is there and takes that signal and conditions it and relays it to the Northstar module est input.

It is a little more complicated, but maybe the crank signal can be decoded by the MS2 or MS3 and a est signal can be sent to the Northstar module thru the Delteq.

It this setup the Delteq would decode the opti and convert it for the Northstar module, and the Megasquirt would use the crank sensor to generate a est signal to send to the Northstar module so it can advance and retard the engine.

I have no idea if this will work because I don't have a delteq, but I have thought about going this way on the LT1 before.
1986 G.N. (sold)
1967 Nova II wagon (sold)
ex-MSer
shortbus
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Re: MS3 and LT1 Camaro

Post by shortbus »

I will retain the optispark. So, the signals to the Delteq (and therefore the downstream GM DIS 8 ) should remain.
shortbus
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Re: MS3 and LT1 Camaro

Post by shortbus »

Okay, so I need help. Ha. I knew this was coming.

I am having trouble when the MS3 is connected to the car -- I can get a stable connection to the MS3 via USB cable.

When it is plugged in to a 9v 600ma wall wart and a stim 2.2 it is fine. I can burn tunes and turn the knobs and the tuner studio gauges change.

My suspicion is the pins are in the wrong place or there is a ground not in the right place.
I have some things I can test there...

Does anyone have a list of what pin goes where on an LT1 harness?

I don't have a digital version of what pins I used, but I will post it when I get in front of it. Maybe someone can see my mistake.
shortbus
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Re: MS3 and LT1 Camaro

Post by shortbus »

I think I discovered my power issue... I had 12v power (pin 28 on ms3) plugged into B30 PCM Pin.

Will kind you individuals take a look at the attached screen shot and see if where I am connecting things makes sense, please?

Here are the docs for the PCM pins:
http://shbox.com/1/1995_pcm_conn_a.jpg
http://shbox.com/1/1995_pcm_conn_b.jpg
http://shbox.com/1/1995_pcm_conn_c.jpg
http://shbox.com/1/1995_pcm_conn_d.jpg

(Edit:I removed screen cap because it was updated for a later post)
Last edited by shortbus on Fri Jul 16, 2010 5:40 am, edited 1 time in total.
Tjabo
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Re: MS3 and LT1 Camaro

Post by Tjabo »

I'm afraid I have nothing helpful to offer about this, but I wanted to compliment you on a really nice table to help organize your setup like that. Very impressive!
--'98 Dodge Neon ACR Turbo - MS3 beta test car - Sold
--'97 BMW 540i/6spd - Single Front/Top Mount Turbo 550+ HP - MS3+MS3X V3.0 - Sold but ripping in Vegas
--'97 BMW 328i 5.3 L33/TH400 Swapped drift car - MS3+MS3X V3.0 Full Sequential - Turbos And Radiator In the Trunk 9.6@144 on a 1.55 60ft
shortbus
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Re: MS3 and LT1 Camaro

Post by shortbus »

Thanks Tjabo. I plan to keep it updated and when I have mine running it will help the next person.
shortbus
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Re: MS3 and LT1 Camaro

Post by shortbus »

Alright guys. I revised the spreadsheet. (I found some mistakes)



What pins from the MS3 DB37 gets plugged into the PCM Battery?
-- Is this Pin 28 (12VDC)?

What pins from the MS3 DB37 gets plugged into the PCM PCM Ignition Feed?

Here is the harness wiring diagram:
pcm_B15-B31_andB30-D3.JPG
(edit: Spreadsheet removed and updated in a later post)
Last edited by shortbus on Fri Jul 16, 2010 7:45 am, edited 1 time in total.
jsmcortina
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Re: MS3 and LT1 Camaro

Post by jsmcortina »

PCM battery won't be used. MS3 doesn't have a "keep alive" input.
PCM ignition feed will go to 12V. (Make sure it is fused.)

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

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shortbus
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Re: MS3 and LT1 Camaro

Post by shortbus »

James: Thank you very much.
Does the factory fusing count?

For those of you following along: here is the newly revised spreadsheet.
pcm_to_ms3_pinout.JPG
atomic6
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Re: MS3 and LT1 Camaro

Post by atomic6 »

Nice diagram, should be helpful some others.

the pin 37 you have triggering the factory fuel pump is negative out and the factory fuel pump relay is triggered by a positive signal so that is going to need addressed.

You could do one of two things, rewire the factory relay to accept the negitive trigger, or you could add another relay to change the squirt output to the positive signal the factory relay needs.

did you figure out how you are going to intergrate the Delteq into the system, or are you going to ditch it and have the squirt control the whole thing?
1986 G.N. (sold)
1967 Nova II wagon (sold)
ex-MSer
shortbus
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Re: MS3 and LT1 Camaro

Post by shortbus »

Atomic6 -- Good catch! Hmm. I don't know the best thing here. I read about a guy with 93 LT1 Camaro (with MS2) and he had Pin37 also going the FP Relay... same circuit 465. He had a note of "Fuel pump relay control (Switched Ground)" but I don't know what he meant.

How do I do the two options that you suggest? :?:

option one looks like just moving wires on the pump? (or at least the wire that go to the pump?)
maybe the second one, that sounds more like what I want.... which is to leave the body and wiring pretty much alone and make my changes in or near the MS3 box.

For the Delteq I have two options - Either supply the Delteq box with the signals it needs or remove it and fire the wastespark directly from the MS3. If I can figure out what the GM DIS8 pins need then I might fire them from the MS3 directly so i can control dwell also.... but I will reserve the brain power for now and just get the MS3 powered up properly and the basics plugged in. So, more on this subject in a bit.
shortbus
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Re: MS3 and LT1 Camaro

Post by shortbus »

Atomic6 -- I think what you mean for me to do is take the neg out and make it positive like this:
http://www.mobileinformationlabs.com/Ho ... ions_1.htm

Forgive my ignorance I don't know how to do somethings but I do know how to find out how to do things.

Is there anything I should know about SPDT relays? I am looking for opinions. Tia.
atomic6
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Re: MS3 and LT1 Camaro

Post by atomic6 »

Take a look at your diagram you posted above with the fuel pump relay in it, and use as a guide for these instructions.

Easiest way would be to move the pin 86 black/white wire over to the pink on 30 then the factory relay will now trigger off of a negative trigger out of the MS3 at your original a7 factory wire.

other wise just put in a relay that inverts the trigger to the positive signal the factory wiring needs. If you need help with the relay setup consult this site.

http://www.the12volt.com/

Very good electrical information and people there.

or directly to the relay stuff:

http://www.the12volt.com/relays/relays.asp
1986 G.N. (sold)
1967 Nova II wagon (sold)
ex-MSer
shortbus
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Re: MS3 and LT1 Camaro

Post by shortbus »

Atomic6 -awesome. Our posts crossed in the lines.

I like the relay idea for now. I saw a great diagram an will do that. Thanks for pointing me in the right direction on this.

I will do this tonight a report back with results.
sjf911
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Re: MS3 and LT1 Camaro

Post by sjf911 »

My stock FP relay was on "default" with switched +12V but became disabled with a switch to ground from the mass airflow sensor (CIS) when no airflow was present. I simply reversed the wiring at the relay socket to correct for the opposite logic "signal" from the MS.
Steve
1983 Porsche 911SC 3.4L, MS-3 v3.57 (pre1.4 alpha1, TS 2.6.14,JBperf I/O extender), MS3X full sequential, RTC, 12x LS2 D585 coil twinplug, PMAS HPX MAF, LC-1, GT35R turbocharged, full-bay intercooler, J&S Interceptor, e85.
shortbus
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Re: MS3 and LT1 Camaro

Post by shortbus »

I have not tried connecting this yet... I broke the rear diff on Sunday. I know that has nothing todo with starting the motor, but I put the ms3 on the back Buber for a bit.

I also ordered a ms3x and want to put that together too.
shortbus
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Re: MS3 and LT1 Camaro

Post by shortbus »

Okay, so I am picking this back up... This is just an update with no real work accomplished yet.

I am getting a 58 tooth wheel made to fit the LT1/4/350 SBC. (60-2)

I was going to buy an EFI Conneciton 58 tooth wheel, but they were 275 dollars and they don't fit under the stock LT1 front cover with out their 355 dollar billet cover. Then I was just going to get EFI's 24 tooth ls1 wheel, but I am scared of the multi tooth stuff and it is also 275 dollars. Getting one made is far cheaper. I'll let you know what happens there.

I picked up 8 D585 coils and the factory wiring for them today. Thanks eBay.

Still needed:
cam sensor - I will probably get EFI connections 2 tooth piece and sensor with the optispark replacement cover. It is 275 dollars or so.
the corvette 58 tooth sensor.

There was a delay for me because I trashed the rear end and had to rebuild it. Since the racing and road coursing stops is about a month I figure I will just wait until then and put the car to bed for winter and work on the MS3+3X install.
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