miner

My wife has a '08 TSX and this weekend we noticed on the highway driving 70+ mph in 6th gear that the engine seemed to not provide a smooth cruising experience. It appeared to be somewhat jerky at times, not real noticable accept a slight hesitation at about 70 mph. I originally thought bad gas, added techron ot the tank and filled up again. This car has burned exclusively Chevron/Texaco gas. No codes were thrown. Is this a DBW issue? No since taking in to dealer since no codes have been thrown. Anyone have any ideas?

SeaJay

What do you mean by smooth cruising? RPM dropping? Lack of response from the pedal?
RPM's increase while the car decreases in speed?

When was your last tune up?

miner

The RPMs did not flucuate at all. The car seemed to speed up and slow down ever so slightly, in quick spurts - that is why the jerky feeling. Was not noticable on cruise control, only when driving without it on. No tune up sice owning car.

Boulder TSX

I have not had this problem, but from various things I've seen on this forum and elsewhere, the symptoms you describe sound like an APP (Accelerator Pedal Position) sensor issue. It senses the relative position of the pedal to the floor...and when it goes bad it apparently starts exhibit the jerky behavior you detailed. It could be other things as well, like fuel injection or fuel filter issues...but I'd check the APP first. The fact that it did not happen with the cruise control engaged makes it more likely, as the cruise does not use the pedal position -- it maintains the numerical speed you set -- once engaged. (Do a search on that term here and you can read more.)

SeaJay

^ What Boulder said.

miner

Thanks guys for your suggestions. Would a faulty APP throw a code?

Boulder TSX

Sorry, since it hasn't happened to me, I can't answer that part of it. But I would imagine some of the archived discussions about it here might go into that.

lando622

Guys,
From my recent experience, Boulder is on the mark. Over the past several weeks, I noticed the same symptoms miner describes and thought it was my imagination or caused by A/C system being overworked in south FL heat. However, this past Friday at the end of a 190-mile road trip, I felt a couple quick "thunks" and up came "Check Emissions System" and "VSA System" error messages on the info center. I was at ~111,870 miles when this happened.

My trusty '06 TSX went into "limp mode" in heavy city traffic and it was disconcerting. After stopping at work to check in with the local Acura dealer, I got back on the road and my TSX drove normally other than the "Check Emissions System" warning was still on (VSA warning cleared itself). Dealer found "Faulty APP Sensor" code P-2138 and I had them replace it as well as complete the ECM/PCM corrosion recall I'd been meaning to find the time to get done.

After the repair, my TSX is back to its old self...lots of pep and smooth as ever. There are a couple threads on APP sensor troubleshooting/replacement. Others have posted that after confirming the error code, they bought the part ($150 or so) and did the repair themselves (20 mins to 1hr, even with little mech/tech skills). Acura dealer repair was ~$400 after 10pct service coupon. If this happens again in another 112K miles, I'd be willing to give it a go on my own, but I needed my TSX for the weekend and had a limited window to get it fixed.

The "thunk" really made me think it was something transmission-related and nothing seemed out of the ordinary until it all hit at once. Good luck troubleshooting your issue.

nj2pa2nc

only time that happens is when I step on and off the gas pedal. My late husband would tell me I was giving him a headache when I drove like that. He would say put the cruise control on.

dontibbetts

I think I've experienced this also but since I just got the car last weekend I was unsure if it was just me being oversenitive, or if it was the DBW, or something else. Thanks to all who posted. I'll do some "APP" research.