• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

Setting up ignition on megasquirt

Alright so after tracking everything back, my 330 ohm was toast no continuity through it. Replaced. Then I had a complete cct from top of r26 to base of Q16.yay.

Put one test lead to a solid ground. The other test lead to the Emitter Leg of the ignition driver (far right leg). if the multimeter beeps you have a solid Base ground.
pass

2) Put one test lead to a solid ground (or the far right leg (Emitter)of the ignition driver) the other lead goes on the middle leg (Collector)of the ignition driver. Use the stimulator get the MS unit flashing that D14 led light like its running. Also you can set your dewll time to the max to make sure your multimeter can detect the ground. every time it flashes you should get a beep. Or if your inverted you will get a beep every time its not flashing.
pass

But this seemed tempermental? It didnt work but then it changed its mind?...

3) set digital multi meter to DC voltage range that will let you see 5v. This is assuming you have a good multimeter not some $5 crap special. Connect one end to a ground and the other to the far left leg (Base) of the Transistor. every time the led flashes on or off depending on your settings you should see a quick 5v blip. I like to use my scope for this stuff but it can be done with a good logging multi meter. I have a multi meter that will tell me the highest voltage detected and how long it was detected for. Also if you don't have something this fancy some cheaper digital multimeter can measure dwell. you will not get a voltage but you will get how long a signal was detected.
pass

Now I have a good meter my trusted greenlee, its reads milivoltages all of the time ( basically the same voltage as if you leave your meter legs in open air) but I did catch glimpses of a 5 v signal, so I figure I can deem this good. Wish i had an osciliscope.
 
Is there some hidden setting in tunerstudio that disables coils from firing or something, i don't know i'm pulling at straws here, i got some SU carbs lying around soo tempting right now.
 
So i think i found my problem, my BIP373 had too much heatsink grease( ouzed over the edge of the insulator) I think caused it to short to the heatsink strip, now I cleaned er up re-installed it and but still no spark, I think the BIP373 is a toast. Thoughts?
 
Most thermal grease is ceramic conductive. It will not transfer a charge. If your using some with metal particles its expensive and will conduct a charge but not that much.

The BIP373 has safety shutdown so its hard to kill them.

Test the DB37 harness pin/wire 36. set you multimeter to audible resistance setting. Ground one end. Connect the other to the DB37 pin/wire 36. Run the ms at a low rpm setting with a max dwell. If its not beeping when the light flashes start testing back to the BIP373.

you said that:
"But this seemed tempermental? It didnt work but then it changed its mind?..."
odd is all I can say about that.

You are close. All we need to fix it grounding that dang coil.
 
yaaaaa were getting close .............. I hope..................... I know your thinking, "what if the new BIP373 does the same thing."
 
yaaaaa were getting close .............. I hope..................... I know your thinking, "what if the new BIP373 does the same thing."

Well im really hoping not, it doesn't make sense though, all the cct. are fine until the BIP, I can trace back the (-) of the coil to the BIP with almost zero resistance, and the d14 LED is flashing therefore its getting a trigger signal and outputting 5v.... so what else can i do?
 
Are you using an insulator between the BIP and heat sink?

Are you sure the coil is good?
Yupp, its there are there is no continuity between the BIP and the heatsink, at least now there is not, I was reading continuity when the heat sink grease was ouzing out. It was high resistance in the thousands- mega. But that might of been the most easy path for current to flow at the time.

And I have tried two different coils, both have perfect readings for primary and secondary.
 
OK.... when this happens to me its best to get a second set of eyes/hands on it to do some testing.

Most places will not work on self built boards. Main reason is they have a standard setup they use when building them so if there is a fault they can find it fast with there standardized tests. Second reason is liability. Too many a person will send someone a board and then blame them for there work. say they broke something else that worked before etc.

Find a local ms-er, make friends (6 pack of beer works for me most the time) and pick the **** out of his brain.

Last option setup a skype video call with a good camera and start testing with one of us online. Not this SAT but next is looking good for me.
 
Thanks meeki!
Iv`e been doing some trouble shooting with a good multimeter. I`ve narrowed it down to a few things. Im not getting 5v at the IGBT, but from `VCC` to leg 3 of Q6 i am. So either my transistor is toast or im not getting my pullup voltage from `squirt 1`.
v3pcb_7.gif
 
Last edited:
There is no pull-up used with internal igniters. If the LED blinks with an ignition pulse then the transistor is fine and you're receiving 5v from the processor.
 
Something is wrong then from the top of r26 to the IGBT you need to get your 5v blip to the Base of the Coil driver.

Also you transistor is fine if the led light flashes. The base of the transistor is getting signal from the CPU allowing the led light to ground (flash).

Dont go testing this transistor leg with out static protection or the CPU removed. Dont go playing with the circuits that lead to the chip if its working.
 
Oh here is the circuit with a pullup on it

424945_3211083248496_1608712812_2569671_1469512063_n.jpg


If you want you could go Wasted spark or COP and further complicate things now :p
The pullup is for giving a Smart Coil / Logic Coil a signal.
 
Back
Top