Rough idle when ambient temp hot

So today it has gotten so bad I almost couldn’t drive it, misfires and backfires exhaust popping, finally a CEL..
P0301 and P0300

 

fantastic, she has self identified the hole. Now you can start to swap over plugs, coils, fuel injectors one at a time to see if the issue follows a hard part. The P0300 usually follows a single hole misfire due to how the PCM detects misfires.

I am asking about coolant usage as this could be an indication of a weeping head gasket or a cracked head.

 

With the engine on when it gets warmed up throw some water in the distributor, try to cools it down and see if gets better.

 

UPDATE: I pulled the coils and there was oil on them and you can see the seals where blowing and sucking oil and dirty in and out of them so replaced the valve cover and tube seals, fuel trims dropped down to 5%


problem still exists but it is at a drivable level but I get random misfires, I reset CEL after valve cover replaced and no CEL yet, I think I may be hearing a exhaust leak, it’s loader when I go from under to listen to it but I’m not sure us that’s an exhaust leak sound, I also took off the heat shield and didn’t see any cracks in the manifold (I paid special attention to the spot where they normally fail on the 1st Gen tacos)


My guess is it’s leaking from the donut seals that’s in between 02 sensor and manifold (second gasket/seal from the engine first being the manifold gasket)

last quarter of the readings (attached pic) is at idle the rest is like 50-60mph

When I’m at idle it misfires
When I accelerate lightly it misfires
When I’m keeping steady gas/speed is runs great
When I’m accelerating hard pressing down on the pedal it runs great

 

You pull the fuel line after the filter and make sure the flow is proper?

 

Faulty spark plug or wire
Faulty coil (pack)
Faulty oxygen sensor(s)
Faulty fuel injector
Burned exhaust valve
Faulty catalytic converter(s)
Running out of fuel
Poor compression
Defective computer

https://www.tacomaworld.com/threads/misfiring-issues.32191/
https://www.tacomaworld.com/threads/misfires-engine-shake.310170/
https://www.tacomaworld.com/threads/misfiring-loss-of-power-abnormal-engine-vibration.178120/

 

Can you elaborate?
With fuel pressure in the system or just pull it off and watch it drip out? Idk

 

The line that comes off the fuel rail and goes in front of the brake booster. Its a 14 mm i think. You need 2 14mm wrenches or a 12mm and a 14 mm. cant remember. Take that off completely and get something to hold the fuel and have someone turn on the key to aux. It will start the fuel pump. If it shoots out real fast then the pump and filter are fine. If it doesn't it may be one of those. Prob the filter.

 

I am having the same issue, 03 taco pre 3.4 2wd. It sound as if it cant push air out of the motor or its not getting gas. Sometimes it stalls completely out. I have it at the shop right now. I will have them look at it and tell me what is wrong, then I will do the work myself if I am comfortable. I will post here if they figure it out.

 

Update: runs bad and almost stalls, had it stall fully once or twice.
I noticed when I go higher than 2000-2500 rpms it runs great, if I’m below that it runs like crap almost stalling, when I’m accelerating under those rpms (2000-2500) sometimes it machine gun misfires BANG BANG BANG one after another like full auto and exhaust backfiring lol
But when I’m accelerating harder above those rpm’s it runs great.
And when the weather is hotter it runs worse, today was cool and misty and it ran comfortably enough for some store runs, but on hot days it’s tough..

my question: do coil packs intermittently fail when they get hotter and does rpm also make a difference?

so what I did i turned on the PWR mode for towing so it shifts higher rpm’s and I can slightly avoid some Misfires

I had the battery and alternator tested at autozone but I’m only 10% confident in them

 

The problem was the coil packs..
The guy who sold me the car gave me the old ones becuase I guess they where changed, but I guess they where some cheap ones that gave out.. thanks for the help guys.
At least in the long search for the problem I found others lol like the valve cover spark plug stem seals

 

Thanks, I will stop them from searching and test my coil packs. Happy you were able to resolve your issues!

Cheers