Pinging at High RPM with 91 octane

Hi TW,

I’ve been noticing my 4.0 Tacoma with about 200K has been pinging more and more at high RPM. I only run 91 octane Top Tier or Chevron and I think it has the ECU TSB( my gas pedal is chopped). The weather right now barely breaks 55F and it still pings. Unfortunately in CA, it is very difficult to find 93 octane and blending unleaded race fuel and 91 would be expensive long term.

I am starting to think its my old fuel injectors or a tired fuel pump.

Has anyone experienced this before and how did you solve it?

Thank you

 

These trucks are designed to run on 87, ever consider your problem may be the higher octane fuel?

 

At 200K you may have carbon buildup in the combustion chamber which can and will cause pinging and pre-detonation.

 

His 06 was engineered based on premium, later a tsb came put saying it's okay for lower octane fuel.

 

Try some good fuel injector cleaner. Redline complete fuel system cleaner works really good.

 

I’ve gone to 87 after using 91 octane for a while and the pinging is worse.

 

Things that generally cause pinging:
Timing
Carbon buildup on piston tops
Cheap gas
Too low octane gas
Wrong temperature spark plugs
Malfunctioning injectors
Running too lean due to O2 sensor