Cylinder 4 misfire - 304

[thebrandon]

I have an intermittent misfire. I had the code pulled up and it was 304 cylinder 4 misfire. This was an issue before I did my timing. When I did my timing I replaced the plugs/wires as well with Toyota plugs and NGK wires. I did keep the old wires just in case.

Before I dive into buying a new coil pack or injector I was hoping to get some advice.

The misfire comes and goes and is not a permanent thing for now.

Where should I start?

 

[tyr0981]

try swapping coil packs with another cylinder, see if the misfire moves with it, before shelling out tons of cash on a new coil pack.

if you haven't already that is....

 

[SamSter0077]

try swapping coil packs with another cylinder, see if the misfire moves with it, before shelling out tons of cash on a new coil pack.

if you haven't already that is....

x2

Had the exact same problem with mine, swapped the coils.. same code (same cylinder location), replaced the injector ($90.00 rockauto.com) and viola.. been running smooth for a few years now.

 

[thebrandon]

I swapped the coils this morning. Taking it for a drive later to see if the misfire happens again. The tough part is that it can go weeks without a problem then it happens for a few miles then stop again. I've put it off too long. Hopefully I can get it figured out soon.

 

[Mellemel]

My 96 4Runner also had this intermittent misfire on #5 Fingers crossed it has gone for good now ! My story goes like this ... Mine began back in December while in 4wd driving through a foot of snow during the first blizzard of the winter. Dumped in a full can of 'Seafoam', parked her overnight and next day it was firing on all 6 again. Howeve I had this misfiring on and off for a few days after then it dissappeared until it started again in May this year, so I changed the plugs and swapped two of the coils and voila, it seems to have gone away ! One thing I did notice that may have been the cause was that I had run the tank down to have the low fuel lamp come on more than once ! My thinking is I stirred up some crap and it was blocking the #5 injector. Maybe wrong but thats what it felt like.

I read on another post that the body of the plugs can develop thin cracks that will cause these misfires too. They appear fine too that's the tricky thing.

Good luck with it.

 

[SilverRidgeRunner1]

cold .67-1.05 Ohms
hot .85-1.23 Ohms
Doing this typically saves me a lot of time, typically found the best way to preform this is when the vehicle has been sitting over night

 

[thebrandon]

After swapping the coil the misfire came back. It is still on cylinder 4. Looks like I'll be shelling out for a new injector.

My plugs and wires are about two months old and my intermittent misfire existed before I changed them. After swapping the coil pack and the misfire not following the coil I am hoping it's the injector.

 

[tyr0981]

i think an injector is all it could be now, unless there's compression problems, then that's is a major deal, involving engine rebuilding....

good luck!

 

[Ol'Blue]

This may help...

I have extra fuel injectors and coils in my parts bin. They are all OE.

I had a bad plug in Cyl#3 not long ago and I replaced all the plugs and injectors at one time. Fixed that issue real quick.

Anyhow, if you need an injector or a coil PM me.

Blue

 

[thebrandon]

Wish I saw that before! I ordered a new one and intake manifold gaskets already.

Thanks though, I appreciate it!

I have extra fuel injectors and coils in my parts bin. They are all OE.

I had a bad plug in Cyl#3 not long ago and I replaced all the plugs and injectors at one time. Fixed that issue real quick.

Anyhow, if you need an injector or a coil PM me.

Blue

Side note, everything should be here Thursday and I can go from there. Then I have to diagnose a weird grinding noise coming from the rear axle . Hoping it's a wheel bearing.

 

[Ol'Blue]

Wish I saw that before! I ordered a new one and intake manifold gaskets already.

Thanks though, I appreciate it!



Side note, everything should be here Thursday and I can go from there. Then I have to diagnose a weird grinding noise coming from the rear axle . Hoping it's a wheel bearing.

You are also going to need to get a complete gasket kit of the fuel injectors. You will need the o ring kit of the injectors. They are a floating style rail so once you take one side out you will need to replace all of them to be safe. It is really easy to rip a gasket ask me how I know and leaking fuel all over the place is not fun at from the fuel rail or the injector.

Blue