Why is my Cylinder 2 Misfiring?

you are right. if it was fuel or cylinder failure, it would be continuous. when the problem comes and goes, usually its electrical or sensor related. i would assume you got a bad sensor somewhere. could be any of sensors that can cause a misfire. like camshaft sensor, crankshaft sensor, maf sensor, or oxygen sensor. list goes on.

 

Same thing I'm thinking. Off to sensor land I go. Thanks man, really appreciate all your help! I'll post back when I have an update

 

Mechanic called and said he's betting it's an injector since it's happening after the engine heats up. He said it's $230 to swap the injector to cylinder 1 to test the theory, see if it happens on another cylinder. Or $400 to just replace the injector. Seems incredibly expensive to me.

I've never replaced injectors before. Is it really that difficult? I'm going to see if I can do this myself.

 

replacing injector is pretty easy and doesnt take that long. but again. you can test the injector using screw driver first. if they all sound the same then the injector is fine. but still replace it just to make sure its not that. just take out the fuse for fuel injection system and unplug the injector and just replace it. just make sure it doesnt leak after you put in the new injector.

 

I'll run that test myself tonight when I get home and get the truck back from the shop. Where is the cylinder 2 fuel injector on my engine? I have the 2.7L 4 cylinder 3RZ-FE. Can't find much info out there on it.

 

the cylinder numbers are pretty much straight forward on these. I own a 2rzfe and the pattern on it is straight. should be the same for 3rzfe.

 

Yep it is, just thinking where the actual injector is. Looks like I'm going to have to remove the throttle body and air intake manifold just to replace the injector. Kind of a hastle. Unsure if I can get to it without removing a ton of parts

 

since its cylinder 2. yes, you are gonna have to remove the throttle body just to do the job right. if you decide to do it, make sure to take a pic of it and mark down the hoses before removinng the throttle body. too many hoses going onto the intake manifold.

 

You might also want to grab a repair manual for your vehicle if you don't already have one. They don't cover everything but can be very useful when doing jobs like this and are nice to have for a quick reference or spec.

 

Just wanted to throw in my 2 cents...

I had an older BMW one time and it had an intermittent missfire on cylinders 2,4,6. (inline 6 engine so no banks).

Very random. Could be driving down the highway and it happens, could be when I start the car up etc....

Ended up being there was a cannon plug for the injectors. 7 wires. 3 of the 7 were corroded and green.(6 for the injectors and one for ground) Replaced the mini harness to the injectors and all went away.

I guess what I am saying is it could be a corroded plug to the injector or the wire is bad. Just an idea.

 

You can get 4 rebuilt Denso injectors for under $125 + $12 in seals. Then It should take an afternoon to replace if you don't get caught up in cleaning the TB and Intake. Once you open it up you'll see all the gunk buildup.

 

Would you advise against just changing the cylinder 2 fuel injector? I can replace the orings on the other injectors that I don't replace. Of course it would be best to replace all injectors, but not sure it's necessary.

 

Did you check the wiring to the injector?

 

I did after your first comment. Wires look to be in good shape so I'm assuming that the injector is clogged up.

 

I just brought up the price on all four just to show what is being charged if you decide to pay someone to do the work. If you change just one it shouldn't be a problem but it would sure make it one less thing to worry about if you took care of all injectors at once. Then you can send yours in to be rebuilt and/or sold or kept as backup.

 

You could try to swap out the injector with the one next to it and see if It starts to missfire on that cylinder before you start throwing money at it. Like swap the one from Cyl 2 with 4.

It doesn't take long for me so It's feasible for diagnosis. Up to you. That would 100% tell you if it's

A) Injector #2
B) Wiring to the Injector


Just an idea

 

I bought all four on eBay, they will be here Friday. Already have the throttle body off and the fuel rail pulled, ready to put in new injectors.

 

Same thing mechanic mentioned to me, I was going to, but once I pulled the fuel rail off I decided I needed to just replace injectors anyways. All four we're very rusty on the outer casing and have black sludge accumulated all over the nozzle and two holes where the fuel sprays out.

I'm hoping this is my issue. The wires look fine, but the majority of the wire is wrapped in black protectant

 

just to swap a sensor? thats highway robbery...

 

For anyone that's doing this job and knows that it's been a long time since their throttle body has been taken off the air intake manifold, go ahead and get yourself a new throttle body gasket. Mine crumbled to pieces when I removed my TB.