I've been following and it's great to see your progress. I'm building a house and I just don't have time to try it this summer. I've only driven my car once this summer. I really need to get it out...

That seems to defeat the whole point of allowing overlapping dwell between coils if/when it's necessary.




You can easily find out by checking voltage drop across the resistor.

LS1's started at 0.060" and then GM released a service bulletin to drop the gap to 0.040" because of misfire complaints once the engines got some miles on them.

The truck 0411 applications with a 4x crank sensor still use a distributor. You're not going to get CNP from that setup. It would require a 24X wheel under the timing cover.

What you've got is pretty impressive.

Could the extra starting time be it synchronizing?

What rpm have you taken it to in the car?

Thinking about it more, there is likely a current limiting...

If the module is charging the coil while the line is floating then it could be a NPN transistor? It gets turned on when the PCM pull-up resistor is connected to it?

I'd think the ignition module more or less has the base of the coil driving transistor connected to that pin.

If you know the resistor in the PCM then it's easy to add an external resistor to...

If it can't go above 4.6V then try using some diodes in series as the load. You could use up to 5 or 6 in series. They will limit the voltage so it can't go above 4.6V. They will also not load the...

What happens when you turn off the code?

I would have to say potting can have it's downsides, especially with a hard material like epoxy. I have been involved with some items at work that were potted and failures were happening due to the...

Wow, it's impressive how well you're making out.

If you need some help with the noise issues let me know. I might be able to come up with some ideas that help. I also might be able to help if you...

Good to hear you're making progress but your video links don't work. 3 coils have to dwell at a time at high rpm? Sure illustrates the limits with a single coil.

Yes, it is possible. Ignore the rising edge of the EST signal. Don't use the EST line to signal coil charging at all. Instead, only use the falling edge of the EST signal inside the external module....

Looks reasonable the way it changes, but what do the numbers mean, is it degrees before the plug fires?

What I wrote was true. Read it again, but don't read into it. With a properly built system, both the timing advance and rpm do not affect the dwell time. Sure, you need to know the timing advance and...

With a properly done single coil ignition system, the timing advance has no effect on the dwell. The rpm is what limits the dwell.

With a properly done eight coil ignition system, the timing...

I don't think you're understanding the maximum 90* of dwell number. This is a physical limit based on the basic engine layout of the LT1 and the fact that a single coil is being used in the ignition...

Sounds like a broken starter and/or block waiting to happen.

Yes, with a single spark control output, there is close to 90* of crank rotation charge time available if you start charging the coil again immediately after it was fired. It can never be a full 90*...

Why can't anyone read a whole paragraph?



As in the PCM must at some point turn the coil on again almost immediately after firing it to always be able to produce 46* of advance. When it does it...

spfautsch

At this point, I definitely would bet against switching to the next coil on each low-res crank signal working correctly. I too highly doubt that the PCM could command 46* advance at any...

Yes Johnny, The basic way I'd do the program is by decoding the low + high patterns to load an 8-bit register with the correct starting pattern (8-bits with a single 1 to represent the current...

The LT1 never used a black block PCM. I'm quite positive the OBDII LT1 PCM was unique to that engine the same as the OBDI PCM was. You can swap between the OBDI and OBDII PCM's pretty much directly....

Looking at your picture, you can take make a decent guess that TDC will be the leading edge of each low res notch since the leading edges are all equally spaced 45* around the disk and it would only...

Getting a plan together first is better than going off half cocked with a "solution". But, you've got it all figured out so go ahead.

Still, this isn't your thread so it's not really your place to...