32 degree spark advance, random misfire

Hey guys. Didn’t want to make yet another thread on a misfire issue but here I am. I’ve got a 2000 Tacoma 5VZ/MT, 4WD. Runs fine. Starts fine, most of the time. Sometimes when I start it warm the engine cranks a couple times and hiccups to life, unlike the 3 5VZs I’ve had before. Two days ago I got in and started it, ambient of about 56°F. Check engine light immediately came on at startup, cylinder 1 misfire and a random misfire. Truck was running fine and didn’t seem to be missing so I thought this was strange. I have extra parts from a 5VZ rebuild I did a few months ago (not this engine) so I threw on a bunch of extra parts just because I had them around. So far I’ve:
- cleaned throttle body
- checked and replaced vacuum lines that were cracked
- checked spark plugs, replaced all three coils with low mileage spare ones
- replaced wires with spares
- checked connection at igniter
- replaced cam sensor
- sanded down/cleaned engine ground and body ground
- replaced fuel filter. This is the only thing I’ve actually paid for so far.
- verified that IAT and ECT read same temps when cold

Thought I had the problem solved. Drove about 35 miles yesterday with no issues. Got in 20 minutes ago (45 deg) outside and the light came back on. Same codes. This led me to monitor other things like STFTs and LTFTs, as well as my spark advance. Both fuel trims appear to be relatively normal while driving and logging them proves this. I bought the truck semi recently and it’s been fine until now (273,000 on it). Previous owner said there was a semi new O2 sensor, and also gave me a current smog with the truck. In the listing he said that the fuel injectors were new, the valve cover gaskets were replaced, and the timing belt/water pump was done.

Now, about the spark advance. I’ve noticed it peak up to 35° of timing in different situations and it normally sits around 14-20 degrees at idle. This is with the AC off. Sometimes while idling I’ll watch it drop to the 0° mark, and then way back up. The truck shudders slightly when this happens. This is only at idle. I plan on doing a compression test tomorrow but I figured I’d get this thread started now.
Do you guys think the timing belt is off? Should a 5VZ be advancing to 35 or so degrees and be sitting so high at idle? I appreciate any/all replies. Thanks.


Closing edit: I figured out the issue. 32 deg of timing is perfectly normal while driving. The fuel injector was in fact new, but still not working properly. Replaced with a used, known working injector and have no more issues.