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DIYPNP Megasquirt COP misfire

Posted: Mon Aug 13, 2018 7:51 am
by S14ILKA
I have 95 240SX KA24DE. Turbo, 1000cc ID, LS truck coils running coil on plug configuration using basic logic configuration output(not waste spark), MS trigger wheel, MS DIYPNP.
I can get all the coils to fire individually, and injectors are working and seem to have a decent spray pattern. I've check base ignition timing and it's dead on.
My problem is when car is running it's having a random misfire constantly. Not one cylinder but it moves around and sounds like a subaru.
Also when I crank to start the car my RPM signal isn't constant and it might go out of sync couple times. I wonder if I'm getting some sort of noise interference. Has anyone seen something similar?
I've attached my tune bin file as well.
Running MS2/EXtra 3.4.2

Edit: I think I might be getting some noise from the spark plug wires I've decided to run. I think they are solid core because their resistance is 600-1000 ohms. Would that cause some issues?

Re: DIYPNP Megasquirt COP misfire

Posted: Mon Aug 13, 2018 1:12 pm
by Ada180sx
Hi,
I run the MSPNP2, but not with COP setup.

Just to cover the bases, you set the base timing (with fixed advance to whatever you decide, I used 15 deg)?
And you are 100% sure that your firing order is correct?

-A

Re: DIYPNP Megasquirt COP misfire

Posted: Tue Aug 14, 2018 7:30 am
by S14ILKA
I'm not sure how to set firing order in TunerStudio. I've looked but can't find it. I've made sure that my coils fire individually as I call them up A-1, B-2, C-3, D-4 so I know that they are hooked up right.
I've locked my ignition timing at 10 degrees and synced it with crank pulley. it starts right up but sounds like subie, I was previously fighting sync and tach pickup problems, but I think it's all caused by noise interference from my $20 351W spark plug wires that I got. I'm pretty sure they are solid core.

Re: DIYPNP Megasquirt COP misfire

Posted: Tue Aug 14, 2018 8:31 am
by Ada180sx
The distributor spins backwards (counter clockwise). As far as I know MS firing order just goes in order of A-B-C-D, etc. So, I think you should be set to A-1,B-3,C-4,D-2.

Re: DIYPNP Megasquirt COP misfire

Posted: Tue Aug 14, 2018 12:21 pm
by S14ILKA
****! I figured megasquirt knows what firing order vehicle is once you select "engine type". Megasquirt just fires ABCDABCDABCDABCD?

Re: DIYPNP Megasquirt COP misfire

Posted: Wed Aug 15, 2018 1:38 pm
by Ada180sx
As far as I know, yes. As long as its just at idle, It shouldnt hurt anything to test at idle.Hopefully you left enough slack to just swap your COP connectors around. I am guessing you are going to know instantly if this solution works because she is just gonna purr...

Once you get your car tuned, share your MSQ. I am interested in running the truck coils also. Although, at my HP level I will probably gain like 1HP...

Re: DIYPNP Megasquirt COP misfire

Posted: Thu Aug 16, 2018 6:43 am
by S14ILKA
Yep that fixed it along with NGK plug wires. I'm sure I could of got it to run on cheap wires but I said ***** it and changed all of it. Firing order was wrong, plug wires were crap, and I had to turn on Noise Filtering ON for crank pickup and "tach period rejection" OFF to be able to rev higher then 2800rpm.
Drove it around yesterday, hit some boost. Got to finish up few things before I go street tune it.