How hard is it to change plug in cylinder #1?

BigE

New member
Hi, first off I just wanted to say I really enjoy this site, it's members contributions, and pics. Currently I have a 2001 4runner with 231K miles which I really love, more now than the day I bought it. I had a tune-up done about 40,000 miles ago and truck currently runs fine with the exception of warning lights :). I am getting a 301/300 code - random misfire in cylinder #1. Was thinking about changing out the plug in that cylinder before taking it to the dealer. Is it tough to get to? Do I run the risk of stripping the threads in the head?? In addition, which cylinder is #1? Assuming I am in the drivers seat.
 
Register to hide this ad
Here's a thread on changing the plugs. It ain't hard at all...

http://www.toyota-4runner.org/3rd-gen-t4rs/59008-how-installing-3rd-gen-spark-plugs.html

Here are the plug locations (props to Elton on Yotatech):

92873946.gif~original


So from the driver's seat it's front right (pass side, closest to the radiator).

5VZFE Cylinder numbers? (3rd gen v6 4runner) - YotaTech Forums

If your plugs were changed at 40K, you shouldn't need new ones unless they put in some single tip plugs by mistake vs. the OEM dual tip plugs. You also might try swapping the coil packs to see if it follows the coil or stays with the plug. Just make sure to put the wires back in the correct positions when you move the coil.
 
Last edited:
More than likely if you are pulling a mis-fire code it's a coil issue. ;-)

Replace ALL of the plugs, reset the code (pull the negative battery cable) and then drive it. You'll now real quick if it's the coil.
 
To reduce the chance of stripping the threads which is unlikely but can still happen. Replace the spark plug(s) ONLY when the engine is cold, or coolest as possible. With the engine HOT, you have a higher chance of taking the threads out with your old spark plugs should they want to strip.
 
oh, and heres another tip, the most likely problem to run into when changing plugs is the broken plug wire... it can cause a pain when you try to get broken pieces of rubber out of your cylinder...

if you havent changed spark plugs, try buying a cheap little plug wire removal tool, it could possibly save you a broken spark plug wire and tons of time and energy
 
Okay, thanks for the great advice! So I started by swapping the cyclinder #1coil pack with the #3 coil pack, problem persisted with the same code. I put in a new plug and new wires and still have the same code. I also replaced the pcv valve to no avail. Any ideas as I am getting close to resorting to the dealer route. Thanks again!
 
Okay, thanks for the great advice! So I started by swapping the cyclinder #1coil pack with the #3 coil pack, problem persisted with the same code. I put in a new plug and new wires and still have the same code. I also replaced the pcv valve to no avail. Any ideas as I am getting close to resorting to the dealer route. Thanks again!

Number 1 fuel injector is the prime suspect now.
 
Ok kinda thought that might be the case. Any idea what that may run at the dealer? Should I do all six at the dealer or one?

Is it something an amatuer mechanic can do? Do I do them all at once if it's all opened up or should I just do the one? Thanks
 
Ok kinda thought that might be the case. Any idea what that may run at the dealer? Should I do all six at the dealer or one?

Is it something an amatuer mechanic can do? Do I do them all at once if it's all opened up or should I just do the one? Thanks

I'm bored at work right now so here it goes...
The dealer is ~$130-170 for the injector + labor. #1 is not under the intake plenum so it's pretty easy to replace. Because of that, I would personally just replace the bad one and leave the others alone unless they give you problems in the future. Besides, we're still not 100% sure it's the injector so don't go spending too much $$ replacing the other 5. It could be a valve or even a head gasket issue but the injector is the most likely candidate at this point. If it was me, I would just go ahead and replace #1 (unless you have been loosing coolant lately which would indicate a HG).

The job isn't very hard since it's on the easy side of the engine. It takes about an hour (or 2 if you don't know the engine well). Buy some new o-rings for all 3 injectors on that side (3 top and 3 bottom). When you remove the fuel rail to replace #1, you have to pull it away from the other injectors and the o-rings shouldn't be reused because they can get scored and leak easily. Also, dab a little Vaseline on the o-rings before you reinstall them so you don't score them going in and cause them to leak.

A few more tips (note when I refer to the fuel rail or fuel line):
When you unbolt the short curvy metal fuel line (in front and on top of the engine) from the fuel rail, be careful not to loose the beveled washer in-between the rail and the line. That washer is directional so pay attention to which way it's facing when you remove it. You can just loosen the other side of the fuel line and swing it out of the way once you disconnect the fuel rail. When you go to tighten this fuel line back up there is no torque setting, the bolts just bottom out and stop so don't overtighten them!

The fuel rail has enough play in it to leave the rear attached to it's line. Just swing the rail out of the way to get to the injector(s).

If all this sounds confusing, it'll all make sense once you're in there doing it. I also did a MotorVac induction cleaning on my engine which cleans the injectors as well as the combustion chamber and valves. I would recommend doing this to help keep the other injectors performing correctly. My mpgs also went up by over 50% (from 10 to 16 avg.) after I did it so it's good to do anyways. Here's my thread if you want to read up on it:
http://www.toyota-4runner.org/3rd-g...ning-horrible-but-not-any-more-hopefully.html
 
Last edited:
Brian,

Thanks so much! I think I am going to attempt this later today and will report back. Thanks again!

Eric
 
Did you figure it out i had both those codes too. I replaced the plugs and they went away. I also found pep boys does a fuel injector cleaning in their gold star package. They hook to your rails and pump cleaner in to bring the injectors back to life. Have not got a price on it yet but have to check it out. I have the chug going on at 50mph.
 

Members online

Forum statistics

Threads
278,316
Messages
3,554,120
Members
248,016
Latest member
Advally Service

Trending content

Back
Top