[jonbill]

Why would it be different with the engine cold and warm if it is an issue with the hardware?
Whats different when the engine is warmed up? Electric cooling fans?

[BearWolf]

Why would it be different with the engine cold and warm if it is an issue with the hardware?
Whats different when the engine is warmed up? Electric cooling fans?

I made a long answer to you before but my browser/this site logged me out and it went buh-bye, and I took a small little break from this project with other important things in life, but I am back at it again now.

No, there's nothing that changes more than the engine warms up. It is pretty much a tractor engine as it is in an Volvo 1800E. Cute package but an old push rod design from the late 50s with added analog fuel injection, which I am abandoning.

It takes about an hour (while I am trying to figure out tuning) before sync losses happen. It took a good 90min last night with tinkering before they started to appear. I don't think this is electronics related since it takes this long. I'm starting to suspect my magnets lose flux as they get heated up from radiant heat from the engine block. I would think if it was anything with the electronics, the issue with sync losses would appear way sooner. Sync losses seem more prevalent at low RPM than at higher. Mind you, the car is not driven. All testing is done with it stationary.

I finally captured this. There are a couple of these drops and they happen when I get the sync losses. What does the value on the Y axis mean or relate to? I am about to turn into an askhole as I am trying to understand all of this.

tooth logger.jpg (136.64 KiB) Viewed 235 times

This is what my creation of trigger setup looks like.

Hall sensor setup.jpg (82.65 KiB) Viewed 235 times

It is placed inside the distributor where the old flip-flop contacts used to be. This is to preserve the original appearance.
I use TI's DRV5021A hall sensors, they have three sensitivity variants and I've tried them all with no difference in performance, triggered by 1/16x1/16 round high-temp magnets in a plastic barrel. I may try stacking magnets and see if it helps. I need to buy some more of those though. I followed TI's reference design with a 10kOhm pull-up resistor and a 0.1-μF capacitor mounted in proximity. From what I gathered, trigger is not supposed to coincide with sync, and that is one mistake I made with the barrel, however, it has no sync losses while engine is cold, so I don't think that matters.

I made a mistake when I bought my TS license. I should've added the MLV as well, so I have very limited capacity of what I can view. Although, I understand very little of it right now but there's a learning curve with everything.

Thanks

[BearWolf]

I think I may have found the issue now and I suspect it is my design. I have 24 magnets for sync running on the outer line of the barrel and one magnet on the inner line. Now, both one sync and the trigger is in line with each other. I lowered resolution to 12 magnets, now with trig offset from sync, and it behaves much better, although I have to play with raising and falling edges to get them offset enough to work without sync loss. I had the car running for over an hour and had only three sync losses. The problem seems to be that there's some interference between sync and trigger. It manifests itself as an instantaneous rpm increase well beyond what the tach is registering and the injectors buzz from rapid opening and closing. Since the trigger is running on a shorter radius it gets more time over the hall sensor as compared to the ones on the outer run thus overlapping them. I may have to design an optical solution or go with lower resolution on sync to like 90 degree on crank and see.