Could bad/weak ignition coil break fuel pump?

[dank41582]

Shade tree mechanic here

2008 Yaris Sedan 200k miles

I swapped in new iridium oem spark plugs from the dealer (routine maintenance, they were way overdue) - the engine sounded great with the new plugs, really quiet but then started rumbling/shaking a bit after warming up. I drove it a mile and then back to the house to try to figure out what was causing the rough idle.
Note: I broke the plastic tab on one of the wire connectors in the process of installing the new plugs and replaced the whole wire connector with a new oem connector from the dealer.

I pulled the plugs out and noticed a lot of carbon on the threads of the new plugs. I cleaned them off with a wire brush and put them back in. The rough idle continued.

I let the car sit for a couple weeks while I was out of town and pondered over what to do to fix the rough idle.

I theorized that the built up carbon on the inner threads of the spark plug holes could be the cause of the rough idle so I pulled the plugs out and used a thread chaser and some anti-seize to clean the threads (there is a lot of carbon build up in the cylinders, the engine has been burning some oil - that issue needs to be tackled in the near future as well). After the thread chasing the vehicle wouldn't start up at all! The engine turns over but won't start. Jumping doesn't help.

I theorized that the anti-seize used in the process of thread chasing could have effected the grounding of the spark plug so I spent some time cleaning as much of the anti-seize as I could out of the spark plug hole. Still not starting.

Bought another set of oem spark plugs from the dealer and put them in. Still not starting.

Today, I realize that the fuel pump isn't turning on. The relay audibly clicks and visual inspection of all of the related fuses hasn't revealed a blown fuse. Its possible that this was in fact the cause for the no-start all along and I just hadn't noticed that the fuel pump wasn't turning on before.

I'm starting to suspect that a bad or weak ignition coil is to blame for the rough idle.. or that the wire connector I replaced isn't cutting it (installed incorrectly). I'll have to test the coils.

Could I have messed up the fuel pump by driving the car with a rumbling engine and bad/weak ignition coil over a couple miles?

I guess its also always possible that a rodent chewed through some wiring while the car was sitting.

[ex-x-fire]

try this and check the codes. https://www.youtube.com/watch?app=desktop&v=9ktM1D0DE58

[dank41582]

I've actually seen that video. I considered that hack but ended up buying a replacement connector from the dealer and installed that instead, like so:
https://youtu.be/NX75iqNqQvM?si=kpVAybzIz2P_4DpD

I assumed that the new connector is doing the job but I should test it before assuming that a bad coil is the problem!

Haven't had any CEL codes strangely. I expected a code indicating a misfire but nothing.

Could a weak connection to the coil or a bad/weak coil cause the fuel pump to break?

[ex-x-fire]

No.