ScottFW

iTrader: (4)

A few years ago my MS took a hit when it was being powered through the stim via a wall wart and I guess we had a power spike in my old townhouse. I made a thread about it that's not worth you reading, but basically I ordered all the components from digikey to replace the entire power supply section of the MS1 schematic.

But the thing is, after that power spike happened the MS was totally dead, not merely acting weird. I had no 5V out of U5, no 12V anywhere on the board because what probably failed were the input protection diodes (zeners). If MOV1 (part of the main power supply, yes?) was the dead part, would the MS work at all?

Since your weirdness seems to be related to the blower or A/C, have you tried NOT running the A/C switch through MS3 for idle up, just put the wire back to stock and see if the MS still freaks out in the same manner?

Freaky Roadster

Or run them from different outputs on the ms3X.

Braineack

iTrader: (62)

I've moved the output to the MS3x (from the mainboard) and no change. The issues is when the a/c switch is pressed...it shares the same ground as the blower motor which is the trigger for the a/c idle up code. For some reason, when those two are connected all hell breaks loose. Now I don't even need the a/c adder code to add, it just freaks out as soon as I flip to fan speed 3, so long as that switch is pressed. It does it according to fan speed, so it's gotta be a voltage dumping issue. Blower motor and resistor pack should be here thursday for that.

In other news, I just found that d19 has failed. It's the ziener diode on the 5V circuit...It's allowing voltage to pass to wrong way (ground to 5v through 1.33ohms). I have resistance on both directions of the DMM leads, should only be one way...I only have spare 22v ones, gotta see if y8s has a spare 5v, otherwise I'll grab one at radio shack tomorrow and see what that does. The rest test okay.

EDIT: it appears that it might be okay, when I test another one on a MS here, it has less resistance through it and no known issues.



In other other news, on the way home form work I raced an S2K with a T54 turbo and beat it... until the turbo spooled and v-tec kicked in. He said he was only running a few pounds and if I had been running 15psi i think I'd be even with it.

y8s

iTrader: (8)

at least blur his plate where you say he was involved in racing.

Freaky Roadster

Funny you should mention D19, mine got hot when I ran 12v to the MS3. Someone recommended using a higher rated diode.
Powered it up again to hook up to my laptop and D19 seems okay now, didn't change it.

Braineack

iTrader: (62)

Maybe one of these will work:





Just to add, it appears the findings in my fuse panel make sense when looking at diagram of how it's wired. So I'm assuming the car's wiring is good at this point, so it brings us back to the MS.

Freaky Roadster

Just remembered something about testing diodes, IIRC you have to remove one leg from the circuit.
Good luck with the other MS

92Miata

iTrader: (3)

I dont think the wiring of the car magicly got messed up, im sticking with the MS being the cause of most of your issues.

But my car likes to idle richer, just depends on how much of the little sputters you will put up with to idle as lean as 15-15.5 .

Braineack

iTrader: (62)

that's to test the voltage the diode clamps at.


I think narrowed it down to something on my 16 pin connector. I'm sharing power and grounds to my LC-1, WB gauge, and oil temp gauge through it. That's the plug that creates all the noise in my speakers...problem is my spare injector and spark output on are in so I cant idle with it unplugged, so I need to start pulling things off it one by one and see what's causing the noise at least.

I've had MS on this car longer than you've been alive, I know what's normal and what it's capable of. I'd love a little sputtery 15.0:1 idle, although I'm used to a butter smooth one at that AFR.

92Miata

iTrader: (3)

my bad, ill stop offering the little help i can.

Braineack

iTrader: (62)

represent!


i honestly appreciate it.

miatauser884

iTrader: (11)

Oscillating idle:

I'm not sure if this helps, but I was retuning my idle tonight and found that if I selected a certain value on the PWM idle duty cycle table it would cause the idle to oscillate. Moving just .4 up or down from this value was usually enough to fix the problem. It seemed like the car reached a point where the algorithm may have been trying to control idle, but didn't have the room to do it if that makes any sense. This switch point happened to be right where I wanted to idle 850 rpm. I just adjusted the idle screw to get it out of the "trap". Idle works like a champ. Idling smooth at 14.8:1 and I can probably lean it out further. I'm using the MarioV14.

Shitty part is any time you change the PWM idle duty cycle it seems to require slightly different PID values, or vice versa, however you want to look at it.

I'm sure I'll still have to adjust the idle duty table as it's warming up, but it's great now when warm.

Damn you brain for continuing to change the title! :

92Miata

iTrader: (3)

Side question for brain since its the same topic, At 15afr on my gauge 15.5afr in TS the idle is rock solid steady at 900rpm but has a slight pop from the exhaust. if i have it idle down at 14afr it doesnt do that.

Is that the same issue you have ?

guess I should add I dont use an IAC valve.

richyvrlimited

iTrader: (1)

Mine does the exact same thing. Get at a certain idle DC% and it goes screwy and oscillates.

Sit above or below that area though and it's all perfect. Very annoying.

Braineack

iTrader: (62)

I don't have that issue. My idle point is pretty much the lowest idle duty %.

It sits at 26.2% most of the time, which is my min duty %. I used to see it up around 32% but actually had to turn my throttle body screw in lower once this issue started happening to be able to idle at 850rpm again. 26.2% had become closer to 1000RPM.

My osciallation is not related to the idle duty. I can lock the idle valve and start pulling fuel, I will hear it miss, then go into a death spin.

Braineack

iTrader: (62)

All the noise I've been hearing in my speakers is coming from one the of RCA cables back to my amp. Even with the car with just key ON, the noise gets louder when I power the LC1 unit and even more so if I just flip the a/c switch down.

Braineack

iTrader: (62)

so even with my rca for my sub pulled (at the amp) and my HU not outputting on that channel, my sub is still pumping hard...

Braineack

iTrader: (62)

(zack morris's phone)

First bit a good news new blower motor might have solved crazy idle issue

Freaky Roadster

Congrats, hope it stays fixed.
Old one must have a short.

shuiend

iTrader: (24)

I am glad the one I sent up helped.