Hey guys, hopefully someone can shed some light on a misfiring issue i am having. I have a 2000 Tacoma Pre-Runner 6cyl and it through a CEL a few times but it ONLY does it after the truck has been driven for a bit, turned off, then started back up in a bit (take it home for lunch from work, then does it when i go back to work). Often times on the way back to work it will go away, the misfiring. It idles rough while its doing it but not bad enough to shut off. I have just replaced all 6 spark plugs with NGK's dual grounded to spec and also have put SeaFoam in the tank and vacuum booster but its still doing it.

I can't seem to figure out why it only seems to do it when its hot and been driven, turned off, then started again. Never does it happen in the morning when its cold.

Any ideas?

Thx

 

you could trade the coil with another cyl and if the missfire moves bad coil or ohm the injector on #1 seen a couple injectors go bad hot

 

Hey thanks for the reply.

Question, wouldnt the code include 2 cylinders misfiring if it was the coil, since they fire 2?

 

Usually yes, but a cylinder has to miss several times for the computer to throw a code so a coil can start to go bad and only have a CEL for 1 cylinder. But, more than likely, it could be a bad coil boot (goes to the plug directly under the coil). They are a lot cheaper than a new coil too and IMO many people unnecessarily replace the whole coil (which come with new boots) @ ~$80-$100 instead of just the boots which are ~$10 or $15.

If you swap coil packs with hole 3 and the miss moves, you can rule out the injector and I would then get all 3 new boots and see how it is. If the miss doesn't move when you swap coils, then chances are it's the injector.

 

Ok so I just swapped the coil and boot from Cyl1 and Cyl5. Will see how she fares tommorow.

Btw, while i was in there i checked the resistance on the 1,3,5 injectors and got the following:

#1 = ~1-5M ohms
#3 = 16 ohms
#5 = 16 ohms

...so maybe the injector is the culprit? What causes high resistance vs no resistance in fuel injectors?

 

Not sure what causes the resistance, but it does look like #1 injector is bad.

 

Any recommendations on where to get a replacement fuel injector and also what brand?

 

OEM; part number is 23209-62040.

try www.toyotapartszone.com for 15% off list price.

The wire harnesses can be brittle around there. To avoid breaking them, members have found wrapping the wires and the wire loom bundles in electrical tape before manifold removal.

 

x2 on OEM. At least it's #1, you got out of having to take the intake plenum off.

 

Ok, so I moved the coilpack from #1 to #5 and I still have the problem but I cant get the truck to throw a CEL. Without that I cant see where its misfiring. Is there any way to help it throw a CEL for the misfiring its doing?

 

BTW, its doing it still at the exact same time. Right at lunchtime midday after having my truck sit for about an hour, then started again to go back to work. The hesitation lasts for about 1 mile then stops. Then the truck runs like a champ from then on.

 

did you use DI-ELECTRIC grease when you changed spark plugs??? this solved the same issue for me!!! that crazy clear gunk in the drop tubes "DI-ELECTRIC" was put there for a reason and many people clean it off and think there is no reason for it but TRUST ME TOYOTA PUT IT THERE FOR A REASON!!!!

 

Its FIXED!!!

I want to thank everyone for their input. I ended up replacing the #1 fuel injector with an BG replacement one and the ohm readings all match up with the rest, even after driving then letting it sit like I normally did to produce the misfiring on #1. FWIW, I did not have to remove the intake plenum, only the throttle body. It was a pretty easy task. I also replaced the o-rings on all the injectors that got removed from the fuel rails.

Thanks again, perfect troubleshooting guys...