Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
I have a 2005 odyssey that is back in the shop. We did a tune up on it on 12-3-2019 plugs and coils. Used NGK platinum plugs and OE coils. Today it’s back with P0301-p0306, all cylinders have misfires; since the tune up the customer has only put on 27,000 miles. I looked at live data a seen a few miss fires on each cylinder that seems to go away as it got hot. Frees frame data showed me a miss in cyl 1 with eng temp at 132 degrees. I Smoke tested the intake and found zero leaks any where… now I’m scratching my head lol. Any suggestions or direction would be great.
If it's affecting all cylinders at idle it's likely either intake/exhaust valve adjustment or a stuck partially open EGR Valve let us know if you need help figuring out which it is and if you have access to scan data and oscilloscope with pressure pulse sensor
I have access to scan data (snap-on Zeus) but no oscilloscope. I have it inside right now, when I go to work in the morning I plan on monitoring live data looking for miss fires on a cold start up. Initially I saw just a few miss fires on cyl. 1-4-5-6 then 2 and 3 joined shortly after, but the longer it ran they better they got. That’s what made me smoke the intake but again, I saw no smoke at all. I did notice a tear in the breather tube, where the clamp rests, this I didn’t notice until after my first post. Not sure if this could be it? Again this one has me scratching my head. It’s also been a long day and I’m exhausted thinking about it lol. Tomorrow I’m back at it lol
A broken boot can definitely cause an issue on any MAF engine though I would expect it to be worse driving than at idle (I guess that would depend if engine flex pushed or pulled the boot)(check MAF reading at idle to see if it's being affected. I can't remember exactly what the pids were for egr position but there are egr pids in scan data. that egr valve is easy to get to you could make a temporary block off plate with a tin can to test it (its easier than pulling valve covers and checking valve lash) that said these motors can suffer from misfires from a lack of valve adjustment. Tyler probably has more information on this than I do maybe he will check in here at some point.
Valves may need adjustment as mentioned earlier, especially if the misses are felt at idle and smooth out as you increase rpm.
I think 05 is maybe too old, but the j35 engines with VCM are known for oil ring issues. I would eyeball a spark plug or two for signs of oil contamination.
There's a feature on the scan tool, I think I'm functional tests. Something like "check mode".
This tightens code set criteria and will allow a code to set in one test drive. I find this helpful when trying to ID a missing cylinder if the car is only setting a p0300, or if the misfire data is not cooperating. It may or may not be helpful in your case to pick out the most offending cylinder and work from there.
Yes, it does have a scope on it, however I’ve never used one before and wasn’t sure how much time I’d have with the car, so learning how to use a scope wasn’t exactly an option which is why I simply said I don’t have one, that being said it looks like I have more time than I originally thought, he will be on vacation until after the 1st so any tips on how to identify this with a scope would be great? Again, when you start it up, you can feel and see the misfires on live data but once the engine heats up they seem to go away.
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