Please help, I can't get rid of my inttermittent miss.

I recently bought a 01 ranger 3.0L "U" (non-flexfuel) 5spd manual as a repo.

The prior owner filled the gas tank with 5+ gallons water.

Upon discovering water at my fuel port, i drained the tank, lines, fuel rail & blew out with air, then installed new fuel filter, new gas, new iridium plugs & wires & fresh oil & filter.

I'm getting an intermittent miss on cylinders 5&6 or cylinders 4&6 depending on the time.

I have replaced the upper intake (when removing fuel rail), and also switched injectors bank to bank. I pulled this several times switching injectors.

Still the miss is always on left bank.

Compression is even & at about avg of 170.

Fuel pump pressure is at 45.

No other codes, just missfires.

Also ran Chevron Techron fuel cleaner & 5 gallons of clean gas through the system, still intermittent miss every drive cycle.

Also did enrichment test with an unlit propane torch around the intake, with no change in idle.

My LTfuel trims are (1) 14% and (2) 9%

My STfuel trims are approx (1) 2-3% and (2) -2 to 1%.

Still intermittent miss on 4,5, or 6.


Please Help with any ideas. Thank you.

 

You need to take this reading at idle with engine >180*, and at steady 1500rpm... Both should be as close to "0" as possible and steady...

Check the B2S1 for switching and bias, you may have an exhaust leak ... Philip

 

Thanks Philip. I repeated test as you stated, notice my Bank two 02 sensor stops switching, and drops to a steady 0 (zero).

Waiting for the exhaust to cool to change out 02 sensor.

 

also, my appologies for posting in the Explorer forum instead of Ranger. Sorry!