Hello everyone, I been having a huge issue with my TL lately it started misfiring. First time it did it I took straight to shop. The thing sounded like a Subaru, found out it was a bad coil. So anyways I have not been driving since I got a new car, so I was getting it ready for winter and after getting that all done. It started bogging a lot during lower rpms and a lot hesitation when you hit the gas. I assumed that the plugs were bad so pulled out the first one it was black and the tip was white, so its running very lean correct me if I'm wrong. When I check the codes all the cylinders were misfiring. I changed them to NGK Iridium so it stopped misfiring for a good 2 weeks. Btw at the same time I check all the coils when I did the plugs and I didn't see any foul coils. Recently my brother has been driving it and it happens randomly around lower rpms and it still hesitates when you give it gas. The check engine light is on and when it starts misfiring it blinks but then randomly goes away which is super strange and stops misfiring. I noticed when I got the car it has a rip around the throttle body intake rubber hose I heard those can cause a misfire as well but I'm not sure if that’s the issue atm. The only thing left to do is compression test and check fuel filter. Btw my TL has 426,000 km lol and it’s a 6 speed she's somewhat running good when she wants to lol. It sounds like it may need a value adjustment in the near future before I get it checked out with the shop, any suggestions?

Let me know guys,
Thanks,

 

Did you let anyone use the car? Reason i m asking because in MT people over rev the car cause a bend valve also lead to misfiring. If so some one must trying to hit that vtec zone from 4th to 3rd (btw this is the worst case scenario)

 

Not really just my brother and I have been driving it, but thats interesting i didn't know that. Is that a common issue for MT? I'm praying that is not the cause.

Thanks,

 

What kind of plugs were in there? Bad coil? How was it bad? Was it burned up?

1. Over rev with bent valve/s
2. Water in the ECU

 

you can over rev any MT car regardless of how much smart computer involve now these days, in AT the computer will take your input and calculate if its safe to do so once its safe then it will let you down shift. E.G if I travel 75 mph in my TL I used paddle trying to down shift into 2nd the computer won't let me do that light still blinking down to 2nd but will jump back to 4th.




In a MT car the computer can prevent over rev on the up shift hence "rev limiter" but computer is helpless when come to down shift and here why. Driver has complete controls on the shifting let say you doing 80 mph from 4th gear decide to take it to 3rd for a sweet zone in Acura MT sweet zone which locate between 3rd and 4th pull.

Once the driver shift into 3rd and let go the clutch the wheel actually spin/power the engine instead of the other way around. let to the valve spring compress and decompress much quicker than original specs not by much let say about .050" (yes fifty thousandth of an inch) decompress more than oem specs for fraction of a second lead to the valve made contact piston. This is why racing engine use titanium or stiffer valve spring for their engine for safety measure in case any over rev.

Here is the thread from begining to end of Justnspace dilemma after letting a friend drive his TL.

https://acurazine.com/forums/problem...32-j37-915065/

here is another thread about flashing misfiring code.

https://acurazine.com/forums/problem...valves-633633/

More can be found on youtube and further searching here.





NOTE: I AM NOT SAYING 100% THIS IS YOUR CASE, THIS IS WORST CASE SCENARIO. MAKE SURE GET IT DIAGNOSTIC FIRST PRIOR TO MY CONCLUSION


Also like the guy above me said check to see any water leaking on top the ecu cause it to short circuit. That also some what common in the TL too.

 

It's called "Valve Float". Basically it means that the engine is spinning so fast, that the spring doesn't have enough time to decompress fully to close the valve, so the valve floats open when it is supposed to be closed. Since the engine is an "interference engine", it means the piston will hit the valve if it is not closed when the piston approaches top dead center.

 

UPDATE!!! Thanks everybody for the help but I think I have found out the problem. My brother came home and the car sounded horrible like its missing on 2-3 cylinders, so I popped the hood, I started messing the with the coils again in the front. Sure enough, I disconnect one of the coils and re plugged it in and it stopped misfiring. I think the one of the coil is bad or the whole electrical connection pack to the coils are bad. I'm going to clean the connection with electrical cleaner and see what happens. I'll let you guys know

Thanks, guys appreciate it

 

Also, the coil pack in the middle when you wiggle the connector it starts to misfire. Bad coil or connection?
Let me know guys

Thanks,

 

More like connection to me.

 

I'm going to clean the connection with electrical cleaner and see if it stops misfiring