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Random Misfire, rough idle, & bog - Need help?

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Random Misfire, rough idle, & bog - Need help?

 
Old 04-20-2019, 01:37 AM
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Originally Posted by Say Chi Sin Lo View Post
Check your spark plug seals too. I had a misfire in cylinder #4, was going to swap spark plugs but didn't even got to the spark plugs. I found a bit of oil on my ignition coil in cylinder #4. Further inspection found oil on the cylinder #2 coil as well. I'm at 138k miles. So I just replaced everything:

https://www.s2ki.com/forums/introduc.../#post24581118
From what I can remember I didn't see oil on the coil packs but I will check. Assuming the plug seals are bad, do I need to replace coilpacks(again), spark plugs(even tho they are new), along with the plug seals?
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Old 04-20-2019, 08:41 AM
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Originally Posted by project2k4 View Post
From what I can remember I didn't see oil on the coil packs but I will check. Assuming the plug seals are bad, do I need to replace coilpacks(again), spark plugs(even tho they are new), along with the plug seals?
I asked myself the same questions:

Coil packs - 130k old, may as well replace them while I'm at it
Spark plugs - previous owner said he replaced them. But that's he said she said, and they don't really break the bank.
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Old 04-20-2019, 08:42 AM
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Originally Posted by project2k4 View Post
Maybe my mind isn't working since it's 5am but what is fpr? How do you check it?
Fuel pressure regulator. The test procedure is in the service manual page 11-145 (00-08 SM).

However, the fuel pressure test equipment is possibly more expensive than the new part.

https://www.hondapartsnow.com/genuin...0-pcx-003.html
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Old 04-21-2019, 03:32 AM
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Just and Update: Did fuel filter, no change, still extreme bog. I pulled the coil packs to check for oil but they were clean. I'm going to pull he valve cover today, & adjust valves if need be. My valve cover gasket needs replacing so at least 'll be able to do that.

Any other thoughts? I was wonder if maybe the fuel pump itself is going. What about TPS? I assume the car decides how much gas to put in based on the position of the throttle. Idk just guessing at this point.
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Old 04-21-2019, 09:57 AM
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I'm having a similar problem that was improved at least temporarily by putting a bottle of fuel system cleaner in the tank, so I'm fairly convinced it's a fuel system issue on mine. It tends to stumble at low RPM when cold with occasional misfires at idle. As it gets fully warmed up, it runs better though idle is still a little bit lumpy. I bought some refurbished injectors to throw in, but also plan to do the valve adjustment and spark plugs while I'm at it. This will be my project for next weekend, so we'll see what happens.
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Old 04-22-2019, 10:00 AM
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Originally Posted by project2k4 View Post
I've seen some videos on how to do the valve adjustment & have the feeler gauges along with the tool to adjust the valve screw. How much does this cost to have a shop do it? Should I still do the fuel filter considering it has never been done? & what is priority?

I've moved around plugs & coil packs thinking the same thing you were but it didn't change & then it started reading random misfire.
Main thing is that the engine should be cold....and if you take it to a shop, a lot of shops are in a hurry and don't wait for the engine to cool down. Shops usually charge $150-250. I have an 04 as well and the few times that i've done a valve adjustment, i've only had to adjust the exhaust valves (which are luckily the easier ones to access). So maybe yours will be the same. Good luck and make sure to take your time doing it or just have a shop do it and make sure they do it properly.
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Old 04-22-2019, 03:55 PM
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Originally Posted by Chris_Lum View Post
Main thing is that the engine should be cold....and if you take it to a shop, a lot of shops are in a hurry and don't wait for the engine to cool down. Shops usually charge $150-250. I have an 04 as well and the few times that i've done a valve adjustment, i've only had to adjust the exhaust valves (which are luckily the easier ones to access). So maybe yours will be the same. Good luck and make sure to take your time doing it or just have a shop do it and make sure they do it properly.
Went to do the valve adjustment but for the life of me, I can't get the valve cover off. Note that with 150k, it has never been off. In videos, once all bolts are out, it pops right off. I made sure everything was unplugged/removed, even shook the engine a bit but nothing. Any tips or tricks to this? I don't want to pry it & damage the head or cover.
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Old 04-22-2019, 04:00 PM
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Originally Posted by project2k4 View Post
Went to do the valve adjustment but for the life of me, I can't get the valve cover off. Note that with 150k, it has never been off. In videos, once all bolts are out, it pops right off. I made sure everything was unplugged/removed, even shook the engine a bit but nothing. Any tips or tricks to this? I don't want to pry it & damage the head or cover.
grab it with both hands and twist/shake it to break the "seal"
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Old 04-22-2019, 06:53 PM
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Originally Posted by project2k4 View Post
Went to do the valve adjustment but for the life of me, I can't get the valve cover off. Note that with 150k, it has never been off. In videos, once all bolts are out, it pops right off. I made sure everything was unplugged/removed, even shook the engine a bit but nothing. Any tips or tricks to this? I don't want to pry it & damage the head or cover.
You can tap it with a rubber mallet to break it loose. Worked for me.
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Old 04-29-2019, 08:33 AM
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Fuel injectors or valve adjustment. I had the same issue and ordered a set of oem injectors from ballade sports and fixed my problem. They were the cheapest seller for OEM. I would check valve clearances first. With your milage this will be one of these two.
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