But, if you're upgrading firmware on a diypnp 1.5 with the sequential module in the car... you might want to think about disconnecting your fuel injectors. Yesterday was rather unpleasant due to gasoline hydro-lock after a firmware upgrade to my brothers car. thread on msextra

I'm clueless to how the fuel pump would even be running during firmware flashing...

Its a 1.6 wired car, using the 'inverted' (ms sends 12v) fuel pump relay. IDK... Even if the FP wasn't running open injectors during a burn isn't cool.

still, that requires the FP output to be active in order to trigger the TIP125. Whenever you flash the FP is disabled.

I've never had issue with seq. fuel flashing on the car, done it numerous times (ms3).

Me too on my car. If it wasn't my idea to fix something that wasn't broke I'd just blame my brother as he always has terrible luck with cars.
It gets to be a real PITA sometimes, i'll do something to my car then it'll just not work, or not work as well on his, or we end up having to replace other ---- due to weird failures.

I'll be unplugging my injectors next time I flash (low imp/seq mod) but that's because they got a bit too hot last time.

It seems a lot easier to me to just remove the MS ECU from the car to flash firmware, a couple of electrical connectors and screws or nuts is good peace of mind vs. unplugging all the injectors and coils...

I must have flashed my FW hundreds of times this past year, pretty much without any issues. I do recall the car not starting and fouling the plugs when I was still new to it all and didn't know to cycle the power after a FW flash- but got nowhere near hydrolock!

I recently flashed my firmware to 3.2.1 release, and I've been having problems with injector 4 with sequential injection. No hydrolock or anything of the sort, but it's running like crap intermittently. It's really kind of weird and it all started after I flashed the firmware. I tried flashing back to 3.1.3 which I had initially, and it still has the same problem.

I've gone through swapping injectors, injector harness, cleaning all connections, etc. and even different coil packs (COPS) and it's still got a weird misfire on cylinder 4 that I never had before. Pretty much the only thing done was firmware flash.... so we'll see if my sequential injection module is damaged or not.

If it's not, I have an extra module that I think I'll buy another diypnp for that I may buy another miata for, lol

I have flashed a lot and never had this, might be safer to disconnect the db37 in future to be safe.

then youd have no powerz.

Sounds like someone has their fuel pump wired to be on all the time when ignition is on!