Slashdawg

I have a 92runner v6 stock 4wd auto w/ k&m air filter, 147,000m.
Here is the problem: While accelerating close to 3000r's I get a popping sound coming from the engine area w/ some (but not much) loss of power (kinda bogs). Then while on the freeway (55-65mph) @ about 2000r's I get a slight jerking motion until about 2500r's then it is fine. I installed a new air intake hose before the problem started. Thinking it was dirty injectors, I filled 'er up w/ high octane gas w/ a bottle of 101+ booster. That worked for a tank or two then the problem came back. Any and all feedback is appreciated.
Thanks a 1,000,000.

Bejiita

Sounds like predetonation, or 'pinging' but what would cause it on a mushy compression engine like a 3.0? Have you checked timing at all? If its detonating when it happens DONT floor it. Id check timing first and see if its out of whack.

Slashdawg

Thanks, I'll check the timing....

Kutter

It might also be fuel starvation. check fuel filter, pump, clean injectors, MAF clean. Lean mixture burns slower and sometimes will ignite the incomming fuel air charge before the intake valve closes causing a backfire in the intake Popping noise and jerky loss of power. Octane boost ofcourse only last until the treated fuel is consumed. An in tank fuel injector cleaner may be a better thing to try. Sea Foam is popular. If your fuel filter is old it should be changed.

fuel Pressure regulator could be checked next.

Slashdawg

Will do... Thanks Kutter!

mochester

yeah duder if a tank of premium and some octane booster shut it up, it is definitely detonation (ping)

Kutter

Could still be lean mixture. Lean air fuel mix also burns hotter than normal. This could be causing the plug. The abnormally high cylinder temps can then contribute to detonation.

Slashdawg

Thanks for the input guys! I fixed it with a basic tune. She runs like a dream....Now on to the problem with the tranny. blaaah!!!!

mochester

hey bro, help me out if you can then, because i've been running 91 for the past couple months to quiet it down


what specifically did you do that fixed it?

Slashdawg

Replaced cap/rotor, wires, plugs, fuel filter, cleaned throttle body. My guy told me to run a tank on Chevron 91.