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I’m sure you already have this, but it’s a good reference.

https://www.lsenginediy.com/crankshaft- ... als-guide/

bubba2533 wrote:I’m sure you already have this, but it’s a good reference.

https://www.lsenginediy.com/crankshaft- ... als-guide/

Yes, I have that. The question I can't seem to find an answer for is;
At what point in that cycle does the #1 cylinder fire? When the sync changes from high to low or low to high?

I read somewhere that when cam signal goes low to high is tdc #1. So computer would adjust spark time based from that.

Cincinnatus wrote:I read somewhere that when cam signal goes low to high is tdc #1. So computer would adjust spark time based from that.

That's what I thought. I just wasn't sure.

There is a learn sequence for that too. But I've never done it.

It's interesting to see on the picture with the crankshaft pulses and the camshaft hi low we see 6 crank pulses for a revolution. Have you gone to 6 or still at 3?

Dylan wrote:There is a learn sequence for that too. But I've never done it.

It's interesting to see on the picture with the crankshaft pulses and the camshaft hi low we see 6 crank pulses for a revolution. Have you gone to 6 or still at 3?

I have the learn sequence but haven't done it yet.
There are 3 pulses per 360 deg of rotation of the crankshaft. The image shows 6 pulses per 720 deg rotation of the crankshaft.
So what it shows is 2 rotations of the crankshaft and 1 rotation of the camshaft.

Ahh very good then

So I got the O2 sensor hooked up today and on the short test run I made it really helped it. I'll be driving it about 60 miles tomorrow, so we'll see how it does.
I'm running one O2 with it hooked to the input to both bank 1 sensor 1 and bank 2 sensor 1. I'm using bank 1 sensor 1 12v to heat it. I turned the DTC off for the other O2.
I've also got the fans running off the computer.

She sounds like she humming along then! If the o2 sensor makes a big difference then that sounds like the tune could use a few tweaks! but thats all part of the fun right

Have you got any pics of what your dizzy looks like, you say you use it for sync signal so i assume its got a 50% on 50% off trigger wheel or similar in it ?

Holden202T wrote:She sounds like she humming along then! If the o2 sensor makes a big difference then that sounds like the tune could use a few tweaks! but thats all part of the fun right

Have you got any pics of what your dizzy looks like, you say you use it for sync signal so i assume its got a 50% on 50% off trigger wheel or similar in it ?

Yeah, I've never changed anything in a Bin file until I did this setup. So I'm learning, and it is fun to play with engines.
I've built a lot of engines for street cars and the drag strip. But they were all carbed engines.

The "dizzy" is a stock Jeep unit, 1996 I think. I did move the trigger wheel about 130-140 deg. I just estimated where it should be.
The pic of the trigger wheel is from before I moved it. I'll have to get a pic of where it sits now.
The other pic is the pickup.