I am having a cylinder 4 misfire. I have replaced the plug and the ignition coil, but still misfiring. Sometimes the CEL won't come on immediately, but after driving for a while (I still notice the engine is not running as smoothly as normal). Any ideas as to what this might be? Most of the threads I have seen have multiple misfires, or the misfire is resolved with a new ignition coil.
P0304 Misfire (not plugs, not coils) (1 Viewer)
- Thread starter e46jab
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- ignition coil misfire
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Spark? Fuel? If you have both then do a compression check.
You'll need to do some more digging / troubleshooting.
Some ideas to get us going in the right direction:
- When did this issue start? Any recent engine work / repairs that may be related?
-How did the plug and coil look when your replaced it for the first time. Did it all come out easily?
- Did you replace the coil with OEM or aftermarket? This shouldn't matter much in regards to troubleshooting / getting this misfire to go away but there's always a chance if you bought a cheapy coil that it's not working properly
- I know you mentioned the plug and coil are OK but could you consider swapping a OEM working coil from another plug over to cylinder 4 to see if this changes your symptoms
- What code does the CEL show when the light comes on?
IDK if any of this helps, I'm just trying to think it all through
Some ideas to get us going in the right direction:
- When did this issue start? Any recent engine work / repairs that may be related?
-How did the plug and coil look when your replaced it for the first time. Did it all come out easily?
- Did you replace the coil with OEM or aftermarket? This shouldn't matter much in regards to troubleshooting / getting this misfire to go away but there's always a chance if you bought a cheapy coil that it's not working properly
- I know you mentioned the plug and coil are OK but could you consider swapping a OEM working coil from another plug over to cylinder 4 to see if this changes your symptoms
- What code does the CEL show when the light comes on?
IDK if any of this helps, I'm just trying to think it all through
has the starter been replaced? I had a rig where the intake gaskets failed, they were aftermarket, well after a starter swap.
found it by using starter fluid lightly around intake
forum.ih8mud.com
found it by using starter fluid lightly around intake
intake manifold gasket failure
working on a customer's rig, random misfires, P0300 codes, rough idle but smooths out above idle. nothing I'm coming up with is helping. BIG Thanks to Paul @2001LC for some guidance, sounding like a vacumn leak. start spraying ether trying to pinpoint a location. seems #5 and #8 intake are...
forum.ih8mud.com
Do you have a long socket extension or screwdriver? Something metal. Makeshift stethoscope. With the engine running, touch it to each fuel injector, other end to your ear, and see if one isn't ticking like the others.
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- Thread starter
- #7
Thanks for the replies! This afternoon, I replaced the fuel injector and drove it around for a little while with no issues (not saying this is the fix, but so far so good). The reason I parked it is that I didn't like the looks of the other injectors on this rail and how they sat back into their respective positions (had a gas leak after driving). I am going to replace the rest of the injectors and see how that works out. Fingers crossed this was the issue!
I am having the same issues. Where did you buy your Injectors?
Failing fuel injectors aren't all that common but I suppose anything is possible . Not to jinx OP but hopefully that was the cure
How much do you want for your old injectors?
PM me if you are interested in selling?
- Thread starter
- #11
ahh I returned them to Advance Auto for the core fee, otherwise I would have PM'd you.
The issue I have now is that some of the injectors are leaking fuel. It looks like they are seated properly and torqued the rail back to factory specs. Any pointers?
Are the seals new?
- Thread starter
- #13
All seals are new but came with the injectors I bought from Advance Auto (the only ones available in my area) Advance Auto Parts - Down for Maintenance - https://shop.advanceautoparts.com/p/carquest-premium-remanufactured-fuel-injector-a212-2364/11450303-P?selectedStore=5690&searchTerm=fuel+injector
I wonder if I should order a seal kit from Toyota?
I wonder if I should order a seal kit from Toyota?
