this is pretty straightforward: I am using ls1 coilpacks on my 13b with a ms1 v3.0. I am still using 3 ignition outputs, I just tied two triggers together on two packs. looks like this:

heehee

so what ouputs do I hook up where? here's what I mean:

spark output A
spark output B
spark output C

which one goes to which of these:
pair of leading coils
trailing coil for rear rotor
trailing coil for front rotor

thanks guys. I'm just confused because stock one of those outputs just goes to a 'trigger toggle' or somesuch.
here's another completely unnecessary and unrelated picture of my engine/car

 

I think you need to use FD mode, where the outputs are Leading Timing, Trailing 1 timing and Trailing 2 timing. FC mode is Leading Timing, Trailing Timing and Trailing Select, which won't work for you.

Awesome looking project!

 

thanks - where can I find info on fd megasquirts? seems like everything is for FC

 

Nobody to my knowledge has tried to get one running on an FD engine aside from the one I helped with myself in 2005.

Ken

 

ken, can you help me a little then? I have everything else ready to go. fuel pump is on, cas has a signal when cranking and the msq is set up correctly to my knowledge. just need to know which spark outputs go where

 

ok update: i wired them up the best way I could figure. I wired it where the led furthest from the serial port is the lead and just guessed which ouput applied to each rotor. I know the leading one is right because that's the way aaron cake has it set in his wiring diagram. all the spark plugs fire for a sec when I turn on the megasquirt, but they don't all fire when it cranks..

i tested it and found that the leading ones werent firing and i figured out that i had switched them in my wiring so i switched the leading and trailing again, where presumably the trailing then wouldnt be firing, but it still wont start at all. it at least kinda acted like it wanted to with them switched. could my timing be way off? i have it set to 65 degrees, no addition. there is gas on the plugs. when i try to start it for a sec then turn it off and back off it makes a nice 'pop' obviously it really wants to work but it doesn't.

I have a feeling that this problem has to do with my megasquirt settings to some extent. if someone could look over my msq i'd really appreciate it. I'm thinking only the spark part is messed up, but who knows.

 

and heres a log of the attempted startup

and whats a good req fuel for non turbo?

Edit: I was told that it's normal for only the primaries to spark during cranking, so that may mean that I don't have any problems. my car still won't start though. any suggestions on where to start?

something that concerns me is that my vaccum line hooked to the motor is not pulling a vaccum during cranking. there are no vac leaks big or obvious enough to cause no vaccum at all. the motor has never been started, it's a fresh build.

 

update 2:
I have fuel and spark. it won't start.

so my next thought went to timing, double and triple checked the cas position. the ms is supposed to be set where the spark is 65 degrees +0 right? and this is pretty much a constant since the system is on a geartrain right? like with miatas, the number can be very different depending on where the cas ended up because it was a missing tooth design. but i dont see how that can be possible on the 13b.

question 1: the 65 degree timing mark is an absolute, right? I've been trying to get it to start moving it back and forward 10 or 20 degrees. at 55 degrees, i got it to fire a couple of times and i got fire out of my exhaust. This leads me to my next question
question 2: it seemed to help to adjust my cranking pulsewidth. the magical area where it seemed to fire but not start was around 4.5-6.0 pulsewidth on cranking. this is on redtop 460s. does that seem like the right area or should it be more?
question 3: my vaccum line hooked to the intake manifold showed no change in pressure during cranking. this strikes me as very odd. even with a vaccum leak or crappy compression, it should at least fluctuate between 80 and 97, but it stayed exactly at 97. i tested the sensor itself by sucking on the vac line, the pressure changes just fine. but no. change. at all. when it cranks. not even from 97 to 96.

 

i've been pondering this for a while now, and I think it might be that the primaries and secondaries are somehow switched. if only the secondaries were firing, the car wouldn't be able to start would it?

 

The leading spark should be the same from FC to FD mode, and IIRC, the trailing timing for FC becomes trailing 1 timing in FD mode, and trailing select in FC mode becomes trailing 2 timing. When cranking (or anytime under 800 RPM), only the leading coil will fire, so at the very least this will help you track down which is leading. A good way could be to disconnect the trigger wires from the coils and just crank the engine. Hook up a multimeter to each of the wires to measure continuity between the wire and ground. Whichever one fluctuates when cranking will be your leading timing.

What size are the secondaries and primaries? On 460 primaries, 4.5 - 6 ms sounds like it's ballpark correct, but it depends on engine temperature a bit (i'm going to assume pretty hot, if you're in TN). Idle pulsewidth should be around 3.5ms, but cranking & starting takes a bit more. I had my turbo running on just the secondaries (1000cc's) for a few weeks til I figured out that I had the connectors plugged into the wrong injectors, so it will run, just very poorly, especially at low loads (low airflow to carry the fuel from the injectors down a much longer path of runner).

Has the CAS been moved? I remember that the MS1 did have certain restrictions for where various pulses should be for best performance, and that the stock FC alignment wasn't ideal. Beyond that, I haven't re-stabbed my CAS in a while, or used MS1 for that matter. The best way of determining it is to use the settings you think are correct, set the timing to 0 (I think you can do this in the menu instead of using -10 fro the map), and use a timing light from the leading coil (once you've determined which output controls it and wired it up, from the first paragraph). You may want to unplug the fuel pump so you aren't flooding the engine and throwing fuel away while doing this. IIRC, the leading coil doesn't have an RPM output, so an inductance-type timing light will be necessary.

Good luck!

 

ok I verified that the proper leading trigger was hooked up, and I verified spark in both rotors.

when I pulled the plugs they had gas on them, so it's coming from somewhere

This issue must be caused by timing, but I can't see how. I set the cas like so:
second notch on the pulley (mine isn't yellow, aftermarket pulley)
put cas in with the lobe lining up to the mark on the cas
i had a picture of what the cas should look like when it's in place, mine matches this.

then I put in 65 degrees with no addition. so the timing should (in theory) be perfect right?

 

when you're cranking does RPM go up and then kinda stay at the exact same number for a while and then go to 0 when you stop cranking, or is RPM constantly changing?

Also, how do you have the wheel decoder set up?

Ken

 

a friend suggested that i may need to pull the car to get it started for the first time on a fresh build. what say you, internet?

edit: ken, the rpm moves around between 70 and 300

the wheel decoder is set up like this:

 

the engine may just be badly flooded; clean off the plugs and crank the engine over with the fuel pump off every once in a while. IIRC, you should use 024 as the wheel decoder routine too. Its more suited to our tooth-count wheels. This won't cause the car to start or not though.

Bump-starting shouldn't really help you get it started, fresh build or not. A little bit of oil in the plug holes to help with maintaining compression might.

 

this morning I did this:
1. made sure the timing was set at 65 degrees in megatune and all the settings were good
2. pulled the plugs and cranked, lots of gas smelling thin smoke came out of the engine. flooded indeed
3. put a little bit of atf into the plug holes
4. cleaned off the plugs with a propane torch
5. put plugs back in

cranked it over, no dice.

edit: went back out and tried, with the timing set at 40 degrees it almost acted like it was going to start one time. it made it to 400rpms and gas-smoke was coming from the exhaust, but it just won't start.

 

What timing are you running for starting it? Are you just using trigger return, or taking it off of the table, or specifying a cranking timing?

 

i set the spark base timing to 65 degrees +0

cranking timing advance is set to 5,

the spark advance setting (which is usually at -10 so that it can be variable) i set to 10.

during cranking it shows 10 degrees btdc on the gauge in megatune

 

First step is verifying it with a timing light... you may even be able to borrow one from an auto parts store; once we know that its timed correctly, then we can start playing with timing to get it to start.

 

right - i'm going to buy a timing light tommorrow. i know that the notches on the crank pulley don't mean TDC though, what designations are they?

 

ok so I have a good diagnosis: the timing light clearly flashes when you turn on the megasquirt, but does not flash when cranking. i've seen the plugs spark, so i'm thinking the spark isn't powerful enough? I dunno. I'm betting it has to do with my ls1 coilpacks and megasquirt config.

all my pullup resistors on the megasquirt to the LEDs are 1k ohm. I'm thinking I might need to make them less resistance, and also confirm that my dwell settings are right

 

Now, an update on where I'm at with this:

-I switched the resistors out for 220ohm (matt from diyautotune suggested "270, or even 100" so 220 seemed like it'd be in the ballpark.)
- I tried to crank again, very bright and clear trigger sparks, more visible sparks on crank, but still no timing light reading

I decided that it must be my grounding and I went about measuring it. my battery dropped from 11.9v to almost 8 volts as measured at the coilpack harness during cranking. yikes. I ran a very thick 8 gauge wire (one of those fancy amp install kit wires, says theres as many strands as a 4 gauge) from the negative terminal to the starter, and this improved my cranking voltage drop from 11.9 to around 10v. still no start though!

So I did one more test: I removed the cas from the engine and turned the key to 'on' and spun the cas wheel with my hand. the plugs lit up like a christmas tree, and got a beautiful signal on the timing light. This indicates that push starting it would probably work, which I plan on trying tommorrow, but I need to get this cranking thing figured out!

What could cause that? I'm using the stock miata fuse box, I extended the 12v starter wire from the stock harness to make it all the way to the rx7 starter. I think the rx7 starter might be a beefier starter unit than a miatas, but i'm not sure.

I also tried using a much larger battery from a minivan. cranked a little faster, but still no start and no signal on the timing light. I didn't measure the voltage drop on that test.

 

If the engine is a new build, have you done a compression test? pouring a little oil down the spark plug holes to help everything initially seal may help too, at least for initially starting it

 

already tried that. my battery voltage to the megasquirt drops too. i'm thinking this might be the problem

 

I just tried to push start it. it brap brap brapped for a second then died. so I checked everything, and apparently all my cranking and a few push start runs drained it of it's 2 gallons in the tank, and the battery voltage was 7.5 volts. yeesh.

 

ah, yea, that sounds like it could be it. A bit of grounding & double-checking/cleaning the power, charging & starting connections could help a lot. Make sure there isn't a lot of oxidation on the battery terminals and the starter terminals; this can cause a large drop in voltage and starting speed.