v2 stim, dead?

[Bimmerjim®]

iv just built a v3 ms2, with a glens garrage coil driver board. i used my old v2 stim to verify the power supply while building using a 6v 400ma cell phone charger as a power supply for the stim, but since i haven't been able to get anything from the main board. connected to my pc, it does not communicate with megatune.

i was told that i can jumper a path on the bottom of the v2 stim with a capacitor (and scratch out the copper pathway) to simulate a vr crank signal. i cant remember what specific cap it was, but its connected from the pin closes to "t1" and goes to the end of that pathway nearest to the db37 connector. again, the copper trace on the stim is now broken.

anyway, i connect the stim to the ms, and when i connect the stim the led's light up just as its connected for a split second, then nothing. i didnt think the 6v supply (actualy 6.7v) was enough to turn on the ms, so i also tried a have a 12v 1a power supply. (witch is actually 16.4v according to my volt meter) i didnt want to fry anything, so i just connected it briefly. for maybe one or two seconds and got the same result as before. the led's light up for a split second when connected.. then nothing. no connection to megatune.

recommendations? advice?

[jsmcortina]

The 6V power supply insufficient, I think the absolute minimum is around 8v.

Have you loaded firmware onto the chip? Most MS2 cards come with the monitor and no firmware. In this condition you will correctly get no comms with Megatune.

James

[Bimmerjim®]

i have not loaded the firmware. ill have to check if the retailer i got it from has the firmware pre loaded.

is that other power supply to much? it says its 12v and 1a, but my volt meter says its 16.something volts.

[jsmcortina]

The chips normally come without firmware. Just try loading it.

As for the power supply, it is probably showing that voltage because there is no load on it. If you have a 1/4 or 1/2W 390R resistor (or a little higher) connect that across the output and then re-measure the voltage. I would expect it to have come down and be safe for the Megasquirt. The max limit is 18V from memory.

James

[Bimmerjim®]

thank you

i loaded the firmware, 2.889, and it communicates with mega tune, but no ignition events. clt, iat & tps work, but nothing else... does that diode work to simulate VR input like i was told?

using that power supply, my stim has been on and running for about 2 hours. the 1/2 watt resistor (r9) is crispy black, but still seems to be working.

[jsmcortina]

You can usually get a signal on the VR input if you twiddle the pots a bit. However, the V2 stim doesn't simulate wheel patterns so it can only do EDIS or distributor.

James

[Bimmerjim®]

so, is there any way to test the vr input with the stim i have? can i change settings in MT temporarily just to test?

also, i set MT for the 4 bar map, but in the realtime display it says barometer 100kpa 29.53, and the map to be 65. im at 2800 ft asl, so it should be about 92kpa. right? why isnt it reading right?

[jsmcortina]

Have you run the "sensor calibration" within Megatune as well?

You can work with the VR input as I said above. However, are you asking for a trigger wheel pattern? In that case no. You need crankwheel pulser or a JimStim to generate it. Or for bench testing you'll need to configure your Megasquirt to use "Basic Trigger" (distributor) and "single coil", then turn it back to normal to use it on the car.

James

[Bimmerjim®]

i configured the map sensor and all reads well now. -1,6 in/hg and 94kpa.

sorry to be so... slow, i try to figure as much out as possible without asking stupid questions. really i do.
when you say:

for bench testing you'll need to configure your Megasquirt to use "Basic Trigger" (distributor) and "single coil",

you mean make the canges in megatune right? no physical changes to the board?

i tried changing the ignition settings in MT (basic setup > tach input/ignition settings) and changed ti to basic trigger, and it grayed out the coil option but its set to single coil. burn, reset ms, still no tach signal.

also, there is no 2 second fuel pump prime. i don't know when that stopped, but i noticed it working just after burning the firmware.