mp3car

Hello. I have a 2005 TL, about 80k miles. Lately, [only] while cruising, I occasionally feel a "misfire" of sorts. The best way to describe it feels as though I am hit with a headwind gust, it's barely noticeable and passengers can't feel anything. No CEL...

Has anyone ever seen this behavior?

jmcmann

Holy smokes! I came here today just to write about the same problem. I have no earthly idea what it could be. I do have a few observations though in the hopes that someone else can offer some thoughts before I take it in to the shop:

My car: 2005 TL, automatic, 100K miles

Sensation: Just as MP3Car described, it feels like I'm being hit by an intermittent headwind. There is an appreciable sense of sudden deceleration. Really a butt-in-seat type of sensation. I know it isn't wind though, as it's only from the front, never the side, and doesn't change no matter which direction I'm driving.

Deceleration: Despite this feeling, I don't notice anything obvious on the speedometer.

Revs: Nothing observable there as well.

Power vs. 'coasting' - Seems to happen mostly under steady light throttle, but that might just be b/c my foot is on the pedal and I "feel" it more.

Speed: More noticeable at higher speeds - talking 65+ here, but occasionally I do notice it at slower speeds as well.

Sound: Nothing I can hear.

Car behaves normally otherwise. Shifts fine, starts/stops, revs fine in neutral, not 'bucking' or knocking like you might get from bad gas.

One weird thing, and I need to test this more, is that I don't think I've felt this happen if I'm running under cruise control.

Possible theories:

Throttle linkage? (might explain the cruise control phenomena)
Fuel flow issue? Pump, filter, etc.
Some sort of issue with the knock/fuel sensor retarding engine/cutting power?
Transmission?

I'd love to get some feedback before I take it in to the shop, sound like a complete idiot, and then get taken for a $500+ diagnostic ride.

Thanks all. (first post btw - but frequent lurker)

mp3car

Crazy timing... There was also another person who posted a "misfiring" problem yesterday or today... But i think he said he has am O2 sensor code... My problems are exactly what you describe. I tried briefly today to out it in cruise control and I dont think I felt it! But I noticed on the way home today that I had it in "manual" and sitting in a gear at 4k RPMs it seemed very noticeable... I know slight throttle variations will obviously be felt in this situation, but this is more than that... I've had this car for 8 years now... Nothing i do to this car is a "first" by any means... One question, can your passengers feel it??? I asked my wife and she cannot... She is going to drive it tomorrow to see if she can when behind the wheel (really more the pedal).

mp3car

One more thing.. The "occasionally" that I said in my original post should really be "every time" because it really seems to be all the time now that I think about it... And btw, looks like i didnt catch that my phone's autocorrect screwed up my point about cruise control! I only broadly have checked, but I think when I had CC on I didnt feel it! The feeling could MAYBE be described as what youd expect to feel if the "averaging" or "integrating" functions that are being applied to the pedal position were royally messed up so that even the slightest pedal movement made a considerable movement on throttle plate position...

mp3car

Change your plugs and run a bottle of fuel injector cleaner like chevron techron... I don't know which fixed it, but I replaced plugs with the OEM NGKs ($10ea from pep boys) and after only 1/4 tank, it's not doing it at all now! Unlike me, maybe try one or the other first to figure out which fixed it....

sdhnc01

I'm a frequent reader and new member. I am having exactly the same issue as posted by MP3Car and jmcmann last week. I have an '04 TL 6SP Manual with 133K miles, owned since November 2003. I know the car very well and just started experiencing the 'misfiring' or loss of power problem. Just like jmcmann, it feels like a headwind or intermittent deceleration at constant highway speeds, say 50+ mph. It will accelerate out of it so doesn't seem to be due to restriction of fuel but likely related to an electrical issue. There's still no check engine light. I have noticed reduced mpg, down a couple mpg from historical but this has been the case for the last several K miles. I haven't started any diagnostics or experiments yet and hoping jmcmann or MP3Car can comment further on their resolution of the problem.

Thanks.

mp3car

You definitely seem to describe the same problem I had... See my last post...

I changed my plugs and poured a bottle of chevron techron fuel injector cleaner and a fresh tank of gas... It fixed it! I don't know whether it was the plugs or the FI cleaner, but I'm happy to see it's fixed. sdhnc01, your plugs may have been changed at 60k or so, and may now have 70k on the second set. If I recall, the manual says it's 100k, but the local dealer said they normally do it at 60k. It only took about 1-2 hours to change all the plugs. The hardest part is getting the back three removed. I didn't follow instructions anywhere or look at the shop manual, but I removed the strut tower brace (need to remove the three nuts on each end, and then three bolts from other brackets that are bolted to the brace) then it was pretty easy to get to the coils and plugs. The trickiest part was perhaps finding an extension that was the right length. Too long and you can't maneuver it to get the socket and spark plug in the hole, too short and it won't reach. a short extension and a universal joint to add an extra 1.5" or so did the trick...

I am curious where you guys live... I'm wondering if a combination of the weather warming up and gas formula changing to summer formulation has contributed to us all seeing it at nearly the exact same time...

sdhnc01

I forgot to mention that I changed my plugs at about 110K and all the plugs were nearly immaculate. I also had to remove the strut brace and used two 3" extensions in order to get the back plugs out. All in all, it wasn't too difficult. I'm in NC and it's been very wet and humid lately. The symptoms of this problem sort of reminds me of the old ignition systems with the points, cap, rotor and wires in wet conditions. I suspect it's related to the coils, coil contacts to the plugs or the plugs themselves and not related to fuel injectors.

mp3car

You bring up a point that I thought about too...

Do I really know that CHANGING the plugs helped? What if one connection was poor for some reason?

And as for the FI cleaner, I kind of doubt that it could have possibly helped all that much considering even after only 20 miles, it stopped misfiring. Bottom line though, it was happening every single day, both to and from work and now it doesn't happen at all (about 30mi each way, about 26 of which is 60-90mph interstate driving).

Since you just changed the plugs, that obviously wouldn't be the first thing I'd suspect either... Hmmmm..... I'm guessing the problem will come back and I'll be back where I was last week scratching my head... we've become spoiled with CELs and DTCs

I hate cars

It's not the fuel system. If the car runs fine at full throttle the fuel system is going to have no problem keeping up at cruise.

I can feel when the AC compressor cycles when I'm at a steady cruise. If I have my foot on the gas, no cruise control, and on level ground the car will lose a mph or so if I don't compensate. Cruise seems to do this automatically. I would see if it has the same problem with the AC off.

There are a lot of things it can be but if it were a misfire you would have a DTC. Misfires cause check engine lights quicker than anything else because they reduce catalytic converter life.

mp3car

BAD NEWS.... It definitely is still doing it, but I can swear it went away for a week.

A/C makes no difference. I am curious, sdhnc1 and jmcmann, where do you guys live? I am in OKC, OK (need to update my profile from KS to OK).

I can't be sure yet, but it MIGHT not do it if cruise control is on (which may point to the pedal position sensor???) It is definitely more noticeable if put it in manual mode and drop it down a few to get the RPMs around 4000-5000. This is true whether it's at 45mph or 80mph... This seems like it may "agree" with pedal position sensor since a slight change in output from the pedal will be more noticeable if you're cruising with the RPMs up that high...

I hate cars, so even ONE misfire will throw a DTC, or does it have to be a few within a certain time period? When it comes to pre-ignition (which I am not saying this is), it seems it would take a good bit more than one to throw a code since that's what the knock sensor is for. I was just wondering if perhaps misfire has an "acceptable" frequency of occurring...

Anyone know exactly how it detects misfires? Is it using the knock sensor to listen for each cylinder fire and if it doesn't hear one when it expects to, then it declares a misfire????

sdhnc01

mp3car and others - I took my TL to a highly recommended local shop (not a dealer) and they found a 'pending' DTC2195 code in the ECM. I think this code is typically reporting a stuck lean condition and maybe associated an O2 sensor. After doing some research, they found TSB 04-016 and reflashed the ECM. I noticed immediate improvement and it's been fine for about 3 days now. I would recommend taking your car to a reputable shop, having them check for DTC's and researching this TSB if you're observing the same symptoms that I addressed earlier in this thread. Good luck and thanks for your posts.

mp3car

Thanks for the info!!!

So a reflash of the ECM fixed it??? You mean actual reflash, like rewriting the firmware???

Btw... Don't know I'd this is exactly the way the TL does it, but here is info related to a method of detecting misfires....

sdhnc01

Yes, a re-programming of the ECM is required. Search TSB 04-016 pdf and you'll find it. Instructions copied from it here.

1. Use the HDS to read and clear the DTCs.
2. Use the HDS to update the ECM/PCM:
• If not already done, load software update
1.012.023 or later onto the HDS.
• In the HDS main screen, click on the
reprogramming icon.
• In the
System Selection
menu, select
PGM-FI
,
and click on the confirmation check mark.
• In the screen that shows the new program, click
on the confirmation check mark.
• In the
Confirm the Control Module Update

screen, click
Yes

mp3car

Forgot link about the misfire detection info... http://www.underhoodservice.com/Arti...i_engines.aspx

jmcmann

Update on my situation...

The good: I know what the problem is now
The bad: It all went to hell about 100 miles from my house, so I had to use a stealership to the tune of $560

I was driving on a highway, doing about 70, when the hesitation problem got real bad. I slowed a bit, and all of a sudden my dash lit up (check engine, both VSA lights), and the car dropped to about 40mph. I made it over to the shoulder without incident and let the car sit for a bit. Figured out there was a dealer about 5 miles away (and across the street from my destination), so I restarted the car, and limped in on local roads where 40mph wasn't going to get me killed.

Turns out it was my accelerator pedal position sensor (APP sensor). They were able to fix it same day at least so I could get home.

Doing some research, this is a pretty common problem. I can't believe I wasn't able to come up with this via searching etc. Just didn't go deep/far-back enough in threads I guess. Plenty of topics, but here is one for reference:

https://acurazine.com/forums/3g-tl-problems-fixes-114/app-sensor-guaranteed-cr%40p-out-803593/

So I'm all good now, car feels great. I'm just ticked I had to drop $560 instead of $150 for the part and 45 minutes of my labor. Maybe this'll be a trigger for someone else to get theirs fixed without incident.

Now about that B4 service (timing belt) and those lower control arm bushings I need to take care of...

mp3car

Looks like this TSX thread is exactly the same problem and was fixed by the sensor replacement! Problem sounds identical, "intermittent dragging sensation when cruising..."

https://acurazine.com/forums/1g-tsx-problems-fixes-128/success-app-sensor-replacement-cured-p2138-non-smooth-accelerator-response-819824/

mp3car

Turns out it was the APP sensor! Eventually went into limp-home mode and threw a code. Turning car off and back on gets it out of limp home mode for the time being.

To anyone reading this in the future, I suggest if you suspect this is your problem, fix it before it gets so bad that it goes into limp home mode. It can cause an accident if you happen to be waiting to pull out and it goes into limp home mode and you don't notice until you hit the gas to pull out in traffic!!! I almost got into one... Luckily I didn't get a big enough break on the left turn yield-on-green so i had to wait for an arrow... had I tried to turn in front of a small break in traffic, i may not have made it!

chay823

I have the exact symptoms going on with my car. Only under steady/maintaining a speed of around 70MPH do I notice the miss or that feeling like a strong wind is blowing toward the car and slowing it down momentarily. I ordered the APP sensor. It sucks that you forked our $560 at the stealership. That part its that hard to change from what I've seen. They should be ashamed for that ridiculous price. Smh.

jbc3

Many thanks to all that discovered the fix to this problem. I have been having identical problems for several months and was afraid that it was my transmission going out ( I am now over 120,000 miles). As others have stated, the symptom was like a gusty headwind and it is not always very pronounced. Trying to get a repair shop to witness the problem, much less diagnose it, is usually a problem.

I just ordered my APP sensor and am looking forward to installing it. I feel great knowing that this might be the issue rather than needing a new transmission. I knew that checking Acurazine was my best source for finding the problem and solution! You guys also helped me discover that my problem with the Check Gas Cap light was a purge sensor that had gone bad.

Thanks again to everyone! This is a great website for Acura owners!