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Discussion Starter #1
Here are the details. I was travelling on the highway and was approaching a fairly large uphill. I made the mistake of leaving the car on cruise control at around 105 km/h (66mph) and the van downshifted hard. Right after that happened, the check engine light started blinking (misfiring). I limped it home and later pulled the codes P0301, P0304, P0306 and P0300. These indicated that cylinders 1, 4 and 6 misfired. What I did was replaced all 6 coil packs and spark plugs. I noticed the front 3 cylinders (#4-6) had foul spark plugs. I read that this is most likely due to the VCM which this motor has. After changing the coil and plugs, I fired it up and it was still running rough and the motor was shaking like it was before. Here's a list of other things I've tried/checked:

1) disconnected the battery to reset the computer
2) all fuses are fine
3) assuming I did a compression test properly, cylinder 4 didn't have compression at all. I didn't check the others because it was starting to rain and I had some trouble getting the hose to screw into the spark plug hole.
4) After I start the engine and disconnect the harness on the front 3 cylinders, it sometimes makes the engine sound worse, indicating the cylinder was firing I presume and sometimes it doesn't make a difference. The back 3 seem to always be firing as the engine chugs when I pull the coil harness.
5) Coils are fine as I've tried swapping them around and pulling the harness

I talked to a mechanic I know and he thinks it's burnt valves or something related to the valves. Other possibilities include bad fuel injector or catalytic converter from what I've read. Or is it something VCM related? The van only has 90K miles and was running Mobil1 full synthetic 5w20. Timing belt was replaced at 60K miles. No issues prior to going up that stupid hill except for some oil consumption from the VCM. Oil was just changed and the level was fine. Van was sitting for about 6 months prior with a batter tender and driven once every 2-3 weeks to get it up to temp.

I plan on taking it to that mechanic I know but wanted to get some input beforehand. Thanks in advance!
 

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Discussion Starter #3
They are NGK coils and ngk G power platinum plugs. I live in the prairies up in Canada so it’s very flat here. This hill is tall in comparison to the rest of the landscape but nothing to tall. I’ve gone up this hill before in this vehicle but perhaps with a smaller load as this time I had my family of 4, 4 bikes and some other gear.
 

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I can't help with your issue but I'd suggest installing a VCM disabling device once you get all this sorted out. It may still be early enough to help some of the plug fouling and oil consumption issues you're having
 

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They are NGK coils and ngk G power platinum plugs. I live in the prairies up in Canada so it’s very flat here. This hill is tall in comparison to the rest of the landscape but nothing to tall. I’ve gone up this hill before in this vehicle but perhaps with a smaller load as this time I had my family of 4, 4 bikes and some other gear.
CEL on? Did you scan it for codes? Sounds like it's VCM related.
 

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Regardless of which cylinders are misfiring, and even if they are all working well, it is a good idea to disable the VCM.
 

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Discussion Starter #16
I'm taking it to the mechanic that I know and report back. He's a mechanic at the Acura dealership so he should know these motors inside out.
 

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Okay I am having the exact same issue with my 07 but I am much farther along in my diagnosis.And still have no idea what is wrong. So far I have replaced 1 coil pack on number 4 cylinder changed all 3 spark plugs on the front bank. Verified that all 3 cylinders 4 5 6 are getting spark. We have ohmed out the fuel injector wires to the ecm and all are good. What is happening with mine is that the fuel injectors are not getting the signal to pulse after the engine has ran for about 1 minute. I have taken it to the local Honda stealership here in Columbia Mo to repair and they said it needed a valve adjustment. and charged me $90 to replace the same 3 spark plugs again along with other stuff they needed to try. Anyway we brought it home and I checked the valves and made sure they were all within tolerance and they were very close but now for sure where they are supposed to be. Also checked the compression on the front 3 cylinders 4 was 220psi 5 was 240psi and 6 was 238psi. sounds high to me but all are within 10% of each other. I thought it might be the ecm but everyone I have talked to has said that would be extremely unusual as the Honda ecms are very robust and don't usually give any problems. Anyway the dealership is telling me now that #4 is continually misfiring and telling the injectors to stop working on the front bank since the misfire count is so high for 1 cylinder. I'm not buying that. This ody has close to 200k on it now and has been a good vehicle until this happened. But now I have about had it with it. I'm tired of throwing money at it. If there is anyone else out there that has had this issue and found a solution Please share what it took to fix.
 

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If you have an EX-L or Touring model, have you muzzled the VCM? VCM is known to cause these issues and can (and should) be disabled with a $100 device. I think this might resolve your issues. Even if it does not, it will help protect you from major engine damage caused by the VCM.
 

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Discussion Starter #19
My mechanic said my cylinder 4 has no compression due to burnt vales. He will have to take it apart and also get the cylinder machined. Suffice to say it’s not going to be cheap.
 

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My mechanic said my cylinder 4 has no compression due to burnt vales. He will have to take it apart and also get the cylinder machined. Suffice to say it’s not going to be cheap.
There is more to this...how does it just burn valves? What exactly happened during the incident?
 
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