>car starts running like shit
>limp it home
>swap one of the coilpacks out with a spare from my parts car
>runs like a top

>>28466796 (OP)
>mfw i diagnose a bad coil pack in front of my dad and older bro by unplugging each one and hearing whether the engine rpm changes or not, both of whom don't do much more than oil and filter changes

>>28466809
>mfw I went for the injector first

>Tfw haven't had to ever consider ignition anything.
Japanese electronics in rust-free locations is tight.

>>28466812
She's a Toyota without a touch of rust m8, but it's wasted spark so the coil fires twice as often and after ~350,000kms you can't really blame it for giving up.
Mind you the coil I swapped in was from an engine with ~370,000kms so....

>>28466814
Radical, some strayan shit to my ears.

>misfire code
>wasted spark setup
>correctly diagnosed it as a bad coil because it suddenly started missing on cylinders 1&4

>>28467406
Strangely my wasted spark coil only started missing on one cylinder, must've been a problem with the internal conductor path rather than the actual coil.
Actually it was still sparking just very weak, so maybe the other plug was just in slightly better condition and still able to fire with the weak spark.

>>28467442
For me, it started missing after heavy load was on the coil, aka a mountain pass going 65mph, it was just starting to give out

>>28467406
>car starts misfiring unusually
>when it would start misfiring was random
>but once it started misfiring it would do it consistently until you shut the car off
>misfire was on cylinders 1 and 3
>obd1 car
>dad has an old obd1 scan tool
>one of the quad drivers in the computer (for fuel injection on 1 and 3) was shutting off
>#3 injector had an intermittent internal fault where it would short out and overload the quad driver
The second time it developed a misfire it was because one of the waste spark coil packs died

>>28467914
Yeah to be fair it might've been slightly missing under load for a while, so if I had a sophisticated ECU I might've had misfire codes too.

>>28467964
Damn that kinda sounds like nightmare fuel to diagnose

>>28466796 (OP)
>replacing failing components with other used components makes me a hackermangeniusbigbrain
No, building your own coilpack gorunding harness so they're not relying on shitty factory ground path through the valve cover to the head to the manifold(s) to whatever bracket the likely corroded factory ground strap is attached to would, though.

>>28468275
The meme is ironic my autistic little friend
But I'm pretty sure the cast iron bracket which bolts directly to the head and also has the the entire earth harness from the wiring loom bolted to it is sufficiently grounded.