DIY LTCC or similar system for LT1s

[spfautsch]

You can count the ign on events to get where you want in the log. I marked the 2 most important areas where led freeze.

I'm wanting to focus on the 2nd crank attempt in MOV2024.mp4 where 2 & 7 stick on and stay on during cranking. I'll try to isolate this today but might want you to confirm.

Are you suspecting that the est line is not driven by the pcm each events ...

The instances where a "stuck" coil is happening at beginnings and ends of crank events don't concern me whatsoever. But the crank attempt mentioned above is highly concerning because something was seriously malfunctioning.

I will try to make a video with controller driving #3 and stock coil the rest of the cylinders.

I'd like to see it start if possible. Don't try to jog the engine / make it malfunction. I want to see it crank and start. If it malfunctions that's great (well not great, but you get the idea).

Whats the overall state of health and age of your battery?

[kur4o]

I just tried to make est line drive a led but failed. Can I ask for quick confirmation est line output 5v when high and goes to zero when low. If I wire a led it should be driven right.

I will look for some schematics too. When I was doing the est led attempt I managed to freeze #1[It was on first crank], only got it on video, no log. Will upload video soon. Since now I never managed to freeze a led on the first attempt.

The battery is almost new and I guess a little discharged with the extended cranking. I will load it with some juice but for now it looks strong on cranking, given the fact I have some powermaster starter that is amp hungry.

[spfautsch]

Actually, I think I see a problem from the video.

Can you confirm the installation of your electrolytic capacitors? The colored markings are denoting the negative side, and it appears they're pointing away from each other. They should be pointing towards each other - i.e. toward the power ground input between them per the picture in this post [link].

Edit: I don't think the est line is a normal TTL output so it won't drive an led.

[kur4o]

I checked the board and they are reversed. I should have uploaded board picture much earlier. You suspect they can`t filter noise that way. I will try to switch them and see how it goes.

Meanwhile, here is the latest video + one older video where engine starts and run on stock coil and controller is hooked without coils.


Edit: The est couldn`t lit the led so I guess it is too low on current. Some really small led without resistor might work. Gm manual says to check est line voltage with voltmeter on AC scale. It will be between fluctuating between 0.5v and 4.6v


https://drive.google.com/drive/folde...OX?usp=sharing

[spfautsch]

I checked the board and they are reversed. I should have uploaded board picture much earlier. You suspect they can`t filter noise that way. I will try to switch them and see how it goes.

They're going to be fried - the electrolyte will have boiled by now. I'm surprised they didn't explode on you.

You're most certainly getting a very noisy 5v output from the 7805.

Be careful removing them you will likely damage the board. Maybe cut the cans off so you can expose the leads on both sides so they present less mass to draw heat away. The solder pads on the board are very thick and suck a lot of heat away from the component through holes.

The est couldn`t lit the led so I guess it is too low on current. Some really small led without resistor might work. Gm manual says to check est line voltage with voltmeter on AC scale. It will be between fluctuating between 0.5v and 4.6v

I wouldn't worry about it until you find replacement caps. The AVR is comparing the high value to a 5v reference that was fluctuating. Same with all the analog inputs.

[kur4o]

After some desolder torture the caps are off. The red one came fairly easy, but the purple was putting some strain on the board side ways, and give me a good 1 hour torture. Do you suggest not putting them back. They seem in good shape.

I will reverse them and give them a try. Do you have some p/n for new ones. Do they need to be canned. I can find easy uncanned, not sure about the canned.

I

[spfautsch]

I wouldn't recommend putting them back. You're only going to have so much luck removing them without damaging the board when you find out the hard way they're cooked. They work similarly to an alkaline battery, and the electrolyte is going to be broken down.

Part #s are in the bill of materials file that came in the release archive. It might be named "BOM" something or another.__