22re In 4x4 Pickup Is Misfiring/missing

[SmileyOr]

Hello all,

Ever since my muffler burned out (in April 2004) and I replaced it with a new 2.25 cat back exhaust with a Dynomax muffler (in May) my engine has had a mis or misfire. Is there a timing issue or other adjustment that needs to be made to offset the increased flow/decreased backpressure ?

I have replaced the rotor/cap and plugs (autolite 64 platinum, old plugs were also misfiring/missing). I even checked the new plugs for burn indications and they all look good/the same. I also ran a can of fuel injector cleaner through a tank of gas and no change was noticed. If it was a fuel injector I assumed I would see a difference in the way the plugs burned. Maybe I need to check them again. I also moved the fuel injector wiring around to see if one was grounding out, but I can't tell if that made any difference or if I even moved a grounded wire enough to prevent it from grounding out.

I notice under a load it seems to run smoother, also runs smoother in cold/moist weather vs warm dry weather. If I'm pulling up a hill it is smooth (in cool weather). As soon as I reach the top of the hill and back off the throttle I get a very noticeable misfire that causes the truck to lurch/kick forward/back and is amplified by drivetrain lag. If I'm rolling downhill and I'm completely off the throttle it feels smooth again. Any slight throttle seems to cause the engine to run rough, yet strong.

Is there a vacuum hose that may be worn that could cause a misfire/mis like this ?

Any help would be greatly appreciated.

SmileyOr

Toyota 4x4 Longbed Pickup 2.4ltr 22RE Fuel Injected

2.25 Catback Exhaust with Dynomax Turbo Muffler

If I show as guest, it's because of my current high security browser settings.

[SmileyOr]

Problem solved ! Help recieved from the Toyota 4x4 forum at Off-Road.com.

After adjusting my timing that was at 11 btdc back to 5 btdc I then tested each wire to see what it could tell me. The #'s 1, 2 & 4 were a consistent flash. The #3 wire was almost on constantly. It was grounding out against the other wires and firing with the #2 and #4 cylinders.

I replaced the spark plug wires and all is well. The timing adjustment has improved the starting ease and will no doubt improve the performance a little as well as the gas mileage some.