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-   -   Having a terrible time starting the car on MSX3 (https://www.miataturbo.net/megasquirt-18/having-terrible-time-starting-car-msx3-72310/)

silvermazda 04-20-2013 11:16 PM

Having a terrible time starting the car on MSX3
 
I have a brain built MS3x. Got all things connected, but it just cranks bad. Timing was jumping between T and 10 on the timing piece. By adjusting the tirgger angle to -16 and cranking advance to 16 I managed to start it by pressing the accelerator down. RPM started/shot up to 3K, AFR was changing slowly (around 14.3) and it misfired when it did, just softly, nothing compared to before where I was cranking and just went plop plop. Possible detonation. Heck even my timing watcher said the crank spun the other direction (once).

Once fired it ran at 25degreees of ignition timing. Also when I let go of the accelerator it very slugishly went down to 2500 it took about 3 seconds.

Any advice? I'm getting quite worked up as I expected an easy install, not a hell no I'm not starting tune.

18psi 04-20-2013 11:44 PM

adjust timing offset so that both the car and ms are at 10* when locked.
proceed to tune car after that

Red91 04-21-2013 12:19 AM

In tunerstudio - basic settings->More Ignition Options-> switch fixed advance from "use table" to "fixed timing" - the default is 10 degrees I think. Then it's up to you to adjust the crank position sensor (wiggle room only) next to your crankshaft pulley until a timing light reads 10* on your pulley. Oem spacing between the trigger wheel and the sensor is a "credit card". Once the car matches tunerstudio you can change the fixed advance setting back to "use table" and move forward tuning. Calibrate your afr table to your wbo2 and calibrate thermistor tables if you didn't already.

silvermazda 04-21-2013 01:03 AM

Got it close to 10* then tried to start it with the accelerator pedal. Shot up to 3K again, let it live this time around. I feared engine damage last time. It slowed to 2200, then let it warm up. Eventually, still warming up it stuck around 1500-2000. My air temp was jumping, so I took a look at it. It had one lose wire. After this was corrected it idled better but its still jumping between 14-16. I'll recheck my O2 wires tomorrow. Hoping to tune idle and eventually drive it :)

Now I have to review if I used the right mark to time it. White or yelllow. HM....I'll look at my FSM.

silvermazda 04-21-2013 01:04 AM

Red91 its off by .5 degrees if I read the white mark right.
Edit: Its the YELLOW mark, so I will continue tomorrow. Match the yellow with the 10 for 94+ cars excluding some 95's.

Red91 04-21-2013 11:15 AM

I think .5 is supposed to be just fine for the 99-00's. Double check the instructions that Brain sent to you to be sure, it's probably mentioned.

silvermazda 04-21-2013 06:10 PM

Okay got it running again, set the timing, timing latency. Works great, but got 3 problems
1. its 80 outside, GM sensor says its 100F
2. it doesnt go above 3K, there's a revlimiter, how and when do I remove it?
3. it wont start again.

silvermazda 04-21-2013 07:26 PM

halp

silvermazda 04-21-2013 07:53 PM

Also do I buy both TS and Megalog viewer?

Red91 04-21-2013 08:02 PM


Originally Posted by silvermazda (Post 1003787)
Okay got it running again, set the timing, timing latency. Works great, but got 3 problems
1. its 80 outside, GM sensor says its 100F
2. it doesnt go above 3K, there's a revlimiter, how and when do I remove it?
3. it wont start again.

1. Did you calibrate your sensor under tools?
2. Only rev limiter is under basic setup. I doubt that's the problem if it won't start again. Did you leave timing fixed? Or set it back to 'use table'?
3. No idea there.

Yes tunerstudioms and megalogviewer are very worth registering.

silvermazda 04-21-2013 11:41 PM

Okay got it to fire again. 15btdc and 10% throttle. Then it got bitchy again and adjusted the 750rpm range.

-Oh the 3,000rpm spark cut is still there!!!! goshdarnit !!!!! I can only enjoy my car in the idle-3K region. SOMEONE HEEEEELP

silvermazda 04-22-2013 02:44 PM

Someone help with the mysterious revlimiter problem?

Braineack 04-22-2013 02:59 PM

John, sorry for the late reply. I'll email you back tonight when im home. The 3K cut is probably the crank/cam pots needing adjustment. Seems the 99+ sensors like them turned differently from the 90-97 that I tend to set them up for. I'll write you up steps to go about readjusting them.

email me your current msq and I can review that too and possibly rework the idle parameters for improvement.

Braineack 04-22-2013 03:08 PM

This is faster than email.

It's most likely the cam sensor adjustable pot, so try this:
First you'll need to slide the mainboard out of the case. Remove the two serial port studs from the USB side of the case. IIRC they are 3/16".

Then remove the 4 screws on the opposite end-plate of the case and you can now slide it out from the two db37 side.

You should be looking at a green expander board and a white daughter-board connected by two ribbons.

On the green board, if you lift the large ribbon out of the way you'll see two white rectangular cube with tiny screws on them. Turn them both back 7-8 times counter-clockwise, then turn the top one, r11, clockwise 3 full turns.

This should stop the 3K cut but we might as well go back in and adjust the crank sensor pot just in case. So remove the two studs from the top db37 holding the green expander in place, then fold it up out of the way for access.

There should be two similar, but larger, pots to adjust on the mainboard under the green expander. Turn them both back 12 full turns coutner clockwise, then turn the bottom one, near the(c) 2005, back 7 full turns clock-wise.

reassemble; dont overtighten the studs on the connectors, they will snap easily.

silvermazda 04-22-2013 03:41 PM

What if I go over the 7-8 turns to back it off? Those little screw things look fragile.

And since I am going to drive it soon. How do I position it away from underneath the brake pedal? (top nut of stock ecu is hard to get at)

Braineack 04-22-2013 03:43 PM

Those pots can turn CCW endlessly without worry. They need at least 7 turns CCW on the expander and 12 CCW on the mainboard to "reset."

I've seen zipties and custom bracketry or even extending the harnesses 4 feet and mounting on passenger footwell. the NB location for the ECU is just plain silly.

silvermazda 04-22-2013 03:54 PM

perfect. And yes I hate the stock ecu area. I've tested it and at the limit I might have a mm of clearance between the back of the pedal and the ecu case. I'll figure something out.

silvermazda 04-22-2013 05:08 PM

okay done-so!

Red91 04-22-2013 06:20 PM

1 Attachment(s)

Originally Posted by silvermazda (Post 1004124)
perfect. And yes I hate the stock ecu area. I've tested it and at the limit I might have a mm of clearance between the back of the pedal and the ecu case. I'll figure something out.

I got mine in there with a combination of the lower bracket and a few tie wraps. It's held up well so far.. But definitely doing extended harness to the passenger footwell if I do another 99-05.

https://www.miataturbo.net/attachmen...ine=1366669210

good luck

18psi 04-22-2013 06:38 PM

1 Attachment(s)
ha

this is why I

https://www.miataturbo.net/attachmen...ine=1366670333


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