Got in the 4Runner this am, started it and it was idling really rough then the check engine light came on. Found a close Autozone and their code reader said "No. 6 cylinder mis-fire"......so I bought a bottle of Lucas fuel injector cleaner and poured it in. But I was kinda far from home (120 miles away) so I headed back. It was highway the whole way but the engine was definately missing/shaking and the check engine light blinked a couple times. Once home, I picked up a brand new set of NGK 4302's hoping to fix the problem....still got a check engine light and she's still missing. :cry:
Anybody have any ideas before I get raped for $89 bucks at the Stealership to diagnose the problem? Any help is greatly appreciated!!!!
Thanks
Todd

 

new distributor cap, rotor, and wires?

 

Nope...just plugs so far......Budget is really tight right now... don't want to replace anything that I don't have to till work picks back up!

 

that would just be my guess as to the most probable cause.

 

my guess: a bad plug wire.

i'd get a set of OEM plug wires from the dealer (about $60) if i were you.

 

The 3.4 doesn't have a distributor cap and rotor.

Sounds like a bad coil pack to me. It could also be a wire that is exposed, so you might want to test that too.

Go to the TIS website for a $10 download of the coil pack/plug wire diagnostic procedure and then use a multi-meter to diagnose the problem. In the long run, you will save money over the $89 dealer charge (or whatever it is).

 

no cap and no rotor on a 97.

they have 3 individual coilpacks on the passenger bank with slave wires going from them to the driver side bank.

 

...I am pretty sure #6 is on the passenger side against the firewall, which means it has a coil pack on top of it. Don't quote me on that though.

 

Please excuse my ignorance....but where the heck is the distributor on these things? All I see is a box on each plug on passenger side with a wire from each running to drivers side!?

 

There is no distributor (like you are picturing anyway).

 

My Haynes manual says #6 is on the drivers side against the firewall.....just called the Stealership.....they have the wires........do the coil packs come with the wires?

 

Those coil packs are $$, so I doubt it. If it was a bad coil pack, the cylinder with the bad coil pack on it would be failing too. You should try moving wires around and see if the missfire "moves."

Or, you could just buy new wires and be done with it. No guarantees though.

 

Firing order:
https://www.yotatech.com/forums/f2/3-4l-firing-order-cylinder-designations-60178/

It is either wires or a plug would be my guess (coil pack usually gives a dual misfire but not always).

.....all 3.4L motors are ditributorless and have coil packs like these:

 

I doubt its the coil pack, I recently spoke witha old timer mechanic that was telling me in 50+ years of working on cars hes only seen 1 bad coil.

I would look at the wire, fuel injector, and plug(recheck it).

I recently had the same symptoms and it turned out my plug was cracked at the electrode.

 

Instead of using a distributor, the 3.4 uses a cam position sensor to determine crank angle and sends a signal to fire the coil packs (1 coil for every 2 cylinders). Very reliable system. I agree, check the plug wires first.

 

Thanks Guys!!!!.....I just finished replacing the wires and it seems to be running fine again! But the CEL is still on..... Do I need to have the CEL turned off or will it go off by itself......or worse....do I now have another problem?

 

pull the ECU fuse for a minute and it should clear...

 

He must have retired before coilpacks were in wide use. Just recently VW had a 1.8T coilpack debacle.

They had to build a new coilpack factory to meet the demand for replacements. Well, it wasn't that bad, but so many failed there was a backlog of weeks for getting them replaced under warranty.