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New to this forum, and pretty new to my car, a 2008 Acura TL Type-S black on black, 6 speed, with factory A-Spec kit. Love the car, have wanted one forever. Bought this in hopes I could avoid working on it frequently, unlike my old Integra's. I have been having an issue with misfires, and cannot figure it out. Any help/insight appreciated!
Keep getting codes for multiple/random misfires, usually for all cylinders. Soon inspecting the coils, 3 were filled with oil (bad valve cover gaskets.) Replaced 3 of the coils, all 6 spark plugs with the correct NGK, valve cover gaskets, spark plug gaskets, and intake manifold gaskets. Misfire persisted approx. 300km later, with occasional flashing at a red light, which would become solid when moving. I then had timing inspected, a compression test, and valve adjustment done at the Acura dealer. Set me back more than I liked, but we were both confident this solved all my issues. Valves are slightmy suited, but still misfires. Replaced OFF valve, cleaned EGR passeges, still misfires. It only SEEMS to be at idle. You can feel a shaking in the chassis, especially when cold, and on the motor (my front mount is bad, fluid leaked). You can also hear a miss in the exhaust pipes, not a constant, but it is there. Any load, including the fans turning on and it seems to quit. Any advice on where to look next? Injectors? Compression test was mint and valves are adjusted. Thanks.
I had that issue when I 1st bought my car and until a couple years ago, 08 tls 6mt also. But only when it was “cold” out (I’m in phx), so 1st start of the day mostly or late at night if it had been sitting a while during winter here mostly. You could hear the spent fuel being burned off more loud than usual and then the miss sound in the exhaust. I’m guessing that’s what your hearing too. If I gave it (& held for a min) a extra 100-200rpm while it was warming up I could prevent the random misfire from coming up most of the time. That of course wasn’t a fix just more trying to isolate the problem and a work around. I also brought it to Acura multiple times to (supposedly) fix the problem. The kept my car over night multiple times to be able to cold start in the morning and whatever else they thought of. They said it was a software issue 1 time, it wasn’t. They said it was a Intake problem (oem intake) then a throttle body issue..., nope it wasn’t. They didn’t find or actually fix it any of the times I brought it to them, but made sure to charge me each time of course. Eventually what I found that seemed to be the cause (on my car at least) was 1 spark plug had worked itself partially loose to where when it was cold it woulda been too loose, causing the misfire. But after the car was warmed up the misfire would no longer happen. It was cylinder 6 on mine iirc, but I think that was just the only spark plug that was loose enuff for me to tell by feel that it was loose. I took all of them out, checked for wear, cleaned them and the coils, then put each of them back in torqued evenly to spec. Since then I haven’t ever had the misfire issue again in about 2 years.
I don’t know if your issue is exactly as mine or where you are/how cold it is there currently. But incase it helps that’s what I did to fix mine. You said you replaced the plugs already so just make sure they’re torqued to spec. Have you checked any of them since to make sure their not cover in oil still/again? Otherwise possibly the VC still has a leak after being replaced. I wouldn’t think so but worth checking at this point if it’s still happening after all that.
Check for vacuum leaks e.g. using a smoke machine, or even starting fluid.
Usually a 300 code for multiple misfires is an universal code that applies to all cylinders.
Need to check operating systems to make certain all are within specifications, but the dealership
should have down that with the equipment.
Check operation of the upstream O2 sensors as a lean mixture can also trip the code.
Thanks for the reply's! I will check the spark plugs, the dealer was the last to touch them. The misfire seems more intense when cold but I assume that's just because it runs a little more rough. The misfire can be felt in the chassis at all times and heard in the exhaust at all times only at idle. Any load it goes away!
Thanks for the reply's! I will check the spark plugs, the dealer was the last to touch them. The misfire seems more intense when cold but I assume that's just because it runs a little more rough. The misfire can be felt in the chassis at all times and heard in the exhaust at all times only at idle. Any load it goes away!
I'd say not spark plugs or coils with multiple misfires.
Yes replaced the off yesterday. Old one seemed good though. Have a new EGR valve as well, but I doubt it's the issue. Timing belt was changed by previous owner, I'm wondering if the cam sensor is bad? Any input there? Thanks!
The grounds look pretty coroded, thanks Canada. I am averaging 9L per 100k mixed driving, so my gas mileage is good. How could I diagnose a bad fuel pump?
Seems like cyl #6 may be the culprit, or something to do with it. Misfire counters on cyl 6 are higher than the rest.
swap one of the coils and check. How are you reading misfire counts?
if coil swapping results in same readings, swap the plugs and double check the part number on the plugs
Was reading misfire counts on my shop's obd2 scanner. Tried pretty much all of that. The misfire stops on the scanner when revved. I'm praying it isn't an exhaust valve. Shouldn't that show on a compression test?
Swapped coils, plugs around tonight after working on a friend's VDub. No matter what configuration, misfire counts are highest on Cyl. 6,5,4. Going to test fuel pressure this week at work. What do you guys recommend for testing injectors? Wish they weren't so buried in this big block Honda!
Leak down can show things a compression test can't. From my experience. J series will usually misfire from a bad coil, valve adjustment or burnt valve (especially if they're tight). Possible bent valves if over revved too.
Well from what I've heard; compression test will let you know if there is a problem, and a leak down test can help determining where that problem stems from. I had another quick look at the scan tool on my break today. Couple things arise. 1. The on board moniter ran a leak check of the evap system, mesuring fuel tank pressure after engine off. Value was -0.38. Some of the live data was:
(At idle)
Both Short and long trim (bank 1) -6.2.
Long term trim bank 2; -9.4
Short trim bank 2; -12.5%. This mean something is causing the engine to run rich? Intake absolute pressure was at 30 kpa. Don't really know how to look at this info, anyone? Thanks guys.
I have had the car at my local Acura dealer, and a very experienced tech has been working on it. He worked on it for 10 hours the other day, checked timing belt, coils, map sensor, and valves again. Said that one of the tapets was worn. Does this motor have a taper of some kind that could wear? Thought since it doesn't have hydraulic lifters it wouldn't..
I don't understand how this works, but previous J32s with bent valves only threw a misfire at idle and it disappears upon revving.... Justn saw this same thing on his bent valves...
I'm betting it's bent valves. The fact that it's only on bank #2 is curious. Are you certain the timing marks line up for the front cam sprocket?
I don't understand how this works, but previous J32s with bent valves only threw a misfire at idle and it disappears upon revving.... Justn saw this same thing on his bent valves...
I'm betting it's bent valves. The fact that it's only on bank #2 is curious. Are you certain the timing marks line up for the front cam sprocket?
with my bent valves, I heard it misfire at idle. the exhaust note was choppy and did not sound healthy at all. At speed, it sounded normal, well more normal than the choppy misfire exhaust note. I could tell I was down on power, running on 3 or 4 instead of all six.
I dont think I had gotten a code for it, until like a couple of days later...the codes were for "Multiple misfires 1,2,3,4,5 and 6." I would clear them with OBDII scanner. Codes would come back, but very random misfire order. one day it would be cylinder 1, the next it would be let's say 5..(not sure, it's been about 3 years since this happened)
but since I knew what had happened, I physically saw and felt my friend put it in the wrong gear.. I didn't perform leak down or compression test and just tore straight into the heads.
Ok I see. The timing belt is lined up perfect. The car drives great, don't notice any power loss as I pull on focus st's easy. Just idle like you were experiencing. Choppy sounding, def some misfiring. Surprised the tech at Honda hasn' thought of a bent valve yet (I've had the car in their because I shamed them into basically doing the work for free)
Ok I see. The timing belt is lined up perfect. The car drives great, don't notice any power loss as I pull on focus st's easy. Just idle like you were experiencing. Choppy sounding, def some misfiring. Surprised the tech at Honda hasn' thought of a bent valve yet (I've had the car in their because I shamed them into basically doing the work for free)
even running on 4 cylinders, I out ran 4 cylinder Honda's and toyotas. you might not think power has been lost, but it def was down on power.
also, car would sound like a boxer engine..almost like an STi.
Has anyone said fuelpump? i know wdpanda did lol.
justnspace is the master guru when it comes to this so take his advice.
My 6mt had similar misfire problems.. which started intermittently that eventually shook like tractor diesel engine.
Had replaced coils, sparkplugs, valve gasket, cleaned egr... and culprit was fuel pump.
u can easily diagnose fuelpump by turning your key to acc. 2 which initiate electronic components then listen for 1-2 second beep coming from back of your car. Also, make sure you are at quiet environment..
The problem I see with used TLs is possible mistreatment from the previous owners. And, due to being favored by younger demographics, 6mts are most likely have been WOT. Which means these cars took years of abuse (shitty gas).. that being said CAT can clog up and may replicate symptoms youre experiencing...
good luck op
Thanks for the insight. The fuel pump primes fine and the fuel pressure is good. I agree that these cars have probably all been driven more aggressively. The J35 is very addicting! I have the dealer doing free work for me, as I also had an injector replaced and nothing they have done has fixed it. So that's a plus! They will be doing a leak down this week for me. I will let you know how that goes! It almost has to be a valve at this point.
Has anyone said fuelpump? i know wdpanda did lol.
justnspace is the master guru when it comes to this so take his advice.
My 6mt had similar misfire problems.. which started intermittently that eventually shook like tractor diesel engine.
Had replaced coils, sparkplugs, valve gasket, cleaned egr... and culprit was fuel pump.
u can easily diagnose fuelpump by turning your key to acc. 2 which initiate electronic components then listen for 1-2 second beep coming from back of your car. Also, make sure you are at quiet environment..
The problem I see with used TLs is possible mistreatment from the previous owners. And, due to being favored by younger demographics, 6mts are most likely have been WOT. Which means these cars took years of abuse (shitty gas).. that being said CAT can clog up and may replicate symptoms youre experiencing...
good luck op
Neither did I.. despite many members had suggested culprit might be that one. The common issues are coils or sparkplugs, at worst scenario blown head gasket or bent valves which are more common than faulty fuse pumps..
I also had valve adjustment done but did nothing.. those seldom cures the misfire issues from what im seeing from forums. once again good luck op
10-05-2017, 10:49 PM
