I'm using:
- ms1 v3.0 with a dual VR daughterboard.
- 1991 motor/cas/yada yada

I set my settings all per aaroncake's writeup and I pull-started my fresh rebuild and it barely ran. I got out the timing light and i couldn't even see the teeth when it was flashing. I tried to go back and forth like 20-30 degrees on the timing to see if it was way advanced or way retarded, but when I changed it that much it wouldn't run at all.

Then I went through the settings and found that they were all 100%, except in the decoder wheel settings i had the trigger set to 'rising and falling'. I changed it to rising, then tried to pull start the car again and got nothing.

The car's battery is dead; I'm gonna swap it out and try again, but I'm trying to think of what could cause that. I have aftermarket pullies, but I double checked that the teeth marks are in the same place as the stock pulley, and I set the leading -5 tooth and lined the cas up on the little indention it has, and it doesn't seem like it's even close.

When the car was running, the cas signal was showing a seemingly accurate rpm signal. Is it possible to wire the cas trigger wires backwards where it can show an accurate rpm reading, but want to fire 180 degrees off? I'm going to try pulling the cas out, moving it about 90 degrees, then seeing if I can see the timing notches with the timing light.

TL;DR: I double checked that I set everything up the way it should be and the timing is way off.


fake edit: Also, I have a cooling problem.

this motor is swapped into a miata, so pretty much nothing is stock. I have the lower coolant hose going into the bottom of an aftermarket aluminum miata radiator, and the top one going into the top, naturally. This motor will heat up REALLY fast. Literally after running for 90 seconds (with the fans on) the radiator is too hot to touch and the coolant temp goes to 200+ degrees. My coolant lines are as follows:
big outlet on top of waterpump housing - > top of radiator
big outlet on bottom of wp housing -> bottom of radiator
outlet next to the coolant temp sensor on wp housing-> heater core
big outlet on the rear iron -> heater core
everything else is plugged.
Any ideas on that one?

 

For the overheating issue if timing is off it will generate a great deal of heat. you can play with the trigger/offset numbers to get the timing closer. And are you locking the timing @-5 for the timing light.

 

yeah I have it locked at -5. I guess the rising and falling setting might make it fire twice a cycle, then it's twice as likely it'd work on shitty timing.

I didn't have time to really troubleshoot it when I was working on it, but I at least made sure my cas was in the correct position relative to the pulley. Then I set the spark on 65 degrees, zero addition.

I'm glad to hear about the timing/heat thing. I posted it here because I thought it might be related.

 

I'm surprised it ran with rising and falling.

The setting needs to be rising assuming TSEL is wired to VROUT. Make sure you have the timing light on the correct leading wire. Even though it's wasted spark, at least with my timing light, it only triggers the light to flash when there is combustion on a particular rotor.

Ken

 

Thanks for the info ken.

I just got a chance to work on this car again and I have updated my diagnosis of the problem. It wouldn't crank start. I figured out that the spark is weaker for some reason in low rpms. I took the cas out and spun it with a drill; The spark is too weak to trigger a timing light below 600 rpms (in megatune.) It visibly sparks every time though. Above 1500 it will trigger the light every time. This explains why I was able to pull start it. Im pretty stumped cause the cas gives a seemingly good reading and the coils fire strong as long as it has some rpms. Any ideas?

 

Not enough dwell voltage compensation.

 

I've been through all the settings in megatune, can you adjust that somewhere else like in an ini file? Btw, I even raised the dwell to the maximum 8ms and it seems like it made a little bit of a difference, but not enough to solve the problem (and it'd probably fry my coils after a few minutes of running)

Btw, I ruled out that the lack of spark isn't because the car is cranking and the voltage drops. I just turned the key to 'on' then spun the cas with a drill, and it behaved like that.

 

wait,

I didn't have those capacitors in place. That would cause that type of behavior wouldnt it?

 

I don't know but it is worth a try to see if it helps.

 

I thought i'd just bump this thread instead of making a new one.

This car unfortunately has been sitting for several months because I live 3 hours away and have school/job/etc.

I'm trying to start it, and:
- I know I have spark and fuel
- the timing should be correct within a few degrees (set the cas properly, using 65 degrees +0 in megatune)
- just got a new battery
- basically I've looked over everything that could possibly cause a problem.

Right now I don't have clt or iat hooked up, but I figured that shouldn't prevent it from starting. I've been playing around with the cranking pulse width for the -40F cell to try to get it to start. I also moved the timing back and forth a few degrees, to no avail.

Also, it's basically a fresh rebuild, it has run before, but for less than a total of 10 minutes.

Right now when I crank it, it tries, and one time it bounced up to 500rpm. It's like ch-ch-ch-ch-ch-chuggachugga-ch-ch-chugga-ch-ch-ch I can hear it firing every now and then, it just won't take off and run. I tried putting a little two stroke oil in the motor, but it didn't seem to make any difference.

I attached a MS log of cranking the car, if someone could look at it i'd appreciate it.

 

just hooked up the IAT sensor, no real difference. it fires right when i crank it, it kinda seems like it can't transisiton from cranking to running. once it goes beyond the 'cranking rpm' it gives up.

Like, when i'm cranking, it shows 200-250rpm, when it goes ch-ch-chuggachugga the rpms can jump to 400 or so, and that goes outside the cranking rpm (which I have set at 300)

 

threw some more oil down the chutes, got it going. it's popping and spitting fire like hell, though.

 

if you got fire at the end of the exhaust its to rich.

 

That's an indication that you need to address the tuning in the leftmost points around atmospheric pressure (95kpa here).

The way I deal with that:

Do what you have to do to the VE table to get the engine started and warmed up initially. Since my "running" and "cranking" injection pulses are the same (1 pulse/revolution), I just watch the injector pulsewidth and see if it's dropping off or going way high when the engine fails to catch, then temporarily alter the table to suit.

Once the engine is fully warmed up and basic idle is roughed in, I lug the engine down with the clutch while watching my wideband (best. tool. ever.) to see what the mixture is doing. Goal is to keep the mixture happy all the way down to a near stall condition. This is very important to have right because if you think about it, when the engine starts it is a lot like coming up from a near stall. When I am done, the engine will pick up RPM with authority.

That is what I was doing in this video of my half bridge GSL-SE engine. It's hard to see the VE table through the sun glare but I'm deliberately lugging the engine down to check stall recovery.

http://www.youtube.com/watch?v=gJ6nuqPg_6w