2009 Tundra Limited 5.7 V8 All Cylinders Misfire Only at Idle

Hi guys

I have a 2009 Tundra Limited 5.7 V8 that's throwing codes P0300 through P0308 (random/multiple cylinder misfires across all cylinders). I've cleaned the MAF sensor and throttle body, checked all the spark plugs (they're brand new), and tested the ignition coils. Everything appears to be in good condition.

I took the truck to Toyota for diagnostics. They performed compression tests, and the results for cylinders 1–8 were: 152 psi, 147 psi, 148 psi, 140 psi, 158 psi, 160 psi, 160 psi, and 148 psi. They also said they found water in the fuel tank and advised me to run the tank nearly empty, refill it with premium gas, and floor it when merging onto the highway to help clear the water from the system.

I've followed all of their recommendations, but the misfire (only at idle) codes for all cylinders keep coming back. Has anyone experienced a similar issue? Any help or discussion would be greatly appreciated. Thank you!

 

Check your grounds. Check the grounds on the fender near the headlight may be loose. I had a random misfire all around and the ground wire to the fender had snapped.

 

Is it the ground wire for the transmission, by any chance?

 

Doesn't hurt to check.

 

I’m having the same issue with my tundra. I’ve changed spark plugs, coils, fuel injectors, air filter, vacuum hoses, oem o2 sensors, etc. The compression was 165 on all cylinders as well. Have you figured out the issue yet?