3RZ "ran out of steam"

2001 3RZ with ~335k miles lost power after trying to accelerate/pass on freeway. Pulled over: Engine would barely start but wouldn't stay running. No DTCs. Scratch that. It had an EVAP DTC that was on for a long time, then went away for a bit, then the CEL came on again about a week prior. I had assumed it was the EVAP again. I had known that the oil was low- there was a bit on the end of the dipstick. It seemed to have gone through the previous quart of added oil pretty quickly.

Checked spark plugs: #1 spark plug is stripped, 3(?) was soaked in gas, other two looked okay. Compression check: 2, 3 at 150 psi, 4 at 185 psi. I didn't try squirting oil in 2 and 3 to see if the compression would come up. When I took stuff apart there was fuel at the rail. Got fuel injectors from RockAuto installed and it cranked and cranked but it didn't even try starting.

1. Might the spark plug being stuck be due to getting smashed by the piston, although I'm not hearing any unusual noises? The starter and whatever else make a significant amount of noise, though.

2. What might 1 of 3 spark plugs being soaked in gas be suggesting? After I towed the truck home, I tried starting it a few more times and it still would barely start but wouldn't stay running.

 

The fuel is probably building up because it's being cranked and isn't starting. That's no help I know but that's probably more of a symptom and not the root cause. My first check would be to see if it has spark and go from there.

 

Is #1 stripped or seized?

 

I'd think that the three plugs that I can check would all be gassy, though. The other two were dry.

 

It turned (harder than it should, I think) but didn't come out.

 

If there's spark, fuel and 150psi of compression I'd think it should fire, hence my suggestion to see if it has spark. Knowing that will send you one direction or another.

 

It looks like I should take off the cylinder head anyway to try to fix the stuck spark plug issue, and see if that reveals anything obviously wrong. What should I do while it's together and I can turn it over with the starter? Here's what I'm thinking.

1. Checking for spark makes sense.
2. Check for DTCs.
3. Check compression again and add oil to low cylinders to see if they'll come up.
4. Check timing.

 

Buying new fuel injectors went like this. With one spark plug soaked in gas, I thought maybe that injector is stuck open. I went to a local junkyard that I know had a 3RZ with injectors (3RZs are uncommon in junkyards) to get those for an inexpensive try at getting the engine going again without taking the head off. The injectors were no longer there, so I called a local auto parts store and one injector is $160. RockAuto had some for ~$25 each. "I might as well get all four for the price of one from the auto parts store." Surprisingly, the original and the new injectors are pink.

If anyone has a good link to a good 3RZ manual (Toyota FSM), that'd be helpful.

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Edit: Here's a '99 Toyota FSM for 3RZs (and some or all of 2RZs). I added a table of contents.

https://www.tacomaworld.com/threads/1999-3rz-fsm.491605

 

It's getting spark for the three plugs and coils. They didn't spark when I had the EFI fuse/relay(?) out. I'm also smelling a bit of gas, so I think it's getting fuel. Does the #1 spark plug being stuck probably or probably not have anything to do with the engine issue?

Here's a picture and instructions from the 1999 Toyota FSM.

 

Is there a way to check the ignition timing with a timing gun/light with plug-on-coil?

Here's most of the page for checking ignition timing on a '99 3RZ, which has plug wires going from two coils on the front right of the engine. I'm not trying to do all of that, just want to see if I can get a timing light to work.

 

Did I likely screw up the (seized? was seized?) spark plug by turning it too much? Should I try some penetrating oil and try to get it out, or should I consider it done and take the head off?

Edit: I tightened it up instead of risking taking it out and it seems fine.