Hesitation/sputtering: need diagnosis help

[ShoNuff]

OK, gang. I've got an 09 V6/Tech which is acting up and the dealer has been unable to properly fix my problem.

Problem/symptoms: At cold start, engine idle is erratic jumping around between 500 RPM and 2500 RPM. At cruising speed, you can feel a shudder of sorts when you let up on the throttle (this is consistent). Sometimes, the car will start hesitating/shuddering even if throttle input is steady - this occurs at all speeds. The CEL is not lit and is apparently not showing any codes. The hesitation varies widely, sometimes being barely noticeable and at other times being rather acute (and unpleasant).

Car has been to dealership twice. The first time, the CEL was lit and threw codes P2195 and P2106 (both apparently relate to the oxygen sensor). Dealer "flashed the ECU." This temporarily lessened the severity of the problem but it didn't go away altogether. Problem gradually got worse over the course of two weeks, so car took a second trip to dealership. On second visit to shop, dealer applied TSB 10-FL-007 and asserts that it can't replicate the problem. Dealer is wrong; the problem persists.

I plan to bring the car to a different dealership next time, but am hoping some of you may have suggestions for what the service department should look for. A few possibilities occur to me:
1) Replace oxygen sensor; 2) check for vacuum leak; 3) check TCM (throttle control); 4) possible blockage in fuel line or filter; 5) malfunctioning fuel pump.

Any other suggestions?

 

[TomT]

I had a similar situation and my dealer "found throttle E sensor fluctuating, internal open circuit needs replacing. Tech removed and replaced throttle positioning sensor,internal open circuit. Tech reprogrammmed ECU update."

Car has been fine since.

 

[ShoNuff]

I had a similar situation and my dealer "found throttle E sensor fluctuating, internal open circuit needs replacing. Tech removed and replaced throttle positioning sensor,internal open circuit. Tech reprogrammmed ECU update."

Car has been fine since.

Awesome - thanks, TomT.

 

[Dave]

I have the same vehicle and have been experiencing the same issues for several months. "Shuddering" or "bucking" when throttle is slightly reduced while traveling at constant speed. Erratic rpm after startup until engine warms up. Also hesitation when accelerating from stop. It got progressively worse over the last several months. Recently the car actually stalled several times while driving.

First service visit in May - car was 15 months old with 25,000 miles. Problems were noticable and annoying but not severe. They cleaned electrical contacts, reflashed ECU(?). Seemed better at first but quickly returned.

Second service in July - Symptoms were more severe than in May, easier to reproduce. Engine sometimes ran rough, stalled on me one time. They replaced Mass Airflow sensor and main relay. Probably reflashed again, don't remember details. Seemed better at first, but after a couple of weeks the symtoms returned.

Third service in August - By the time I got it back to the dealer, the symptoms were even worse than in July. It was essentially undrivable. They installed ETC actuator and replaced Throttle Body assembly. They also replaced 2 Oxygen sensors.

Got the car back 2 days ago and I am confident all issues have been fixed. It drives great, smooth as silk. I now love my car again!

 

[PSL]

ShoNuff, I have found the code readers to be accurate most of the time. If your car threw those two codes and the dealership didn't replace the affected o2 sensors, throttle body, or throttle positioning sensor, I would stay after them to fix it. You can buy an OBDII scanner for about 100 bucks at Sears or a parts store and pull the codes yourself if it starts acting up again. I bought one awhile back because I have a few cars in my family to maintain and it is sometimes difficult to get a straight answer and solution from dealership and or mechanics. I keep my OBDII reader in the trunk beside the spare tire incase I need it while on the road. Peace -

 

[ShoNuff]

Thanks, all. My Genny is now at a different dealership, and this dealership says that the fuel pump has gone bad and needs to be replaced. They've got the car until next Tuesday, when the new pump is supposed to be put in (I've got a loaner a.t.m.). I'll update everyone with how this most recent fix works out.

 

[STREETS]

What loaner did they (give?) you?

 

[ShoNuff]

What loaner did they (give?) you?

Just a Sonata (a 2010 model), but a v6 loaded one - not bad at all. Still haven't heard from the dealership yet today. Hmm... methinks I'm not getting my Genny back today.

 

[jpfx]

I was going to suggest clogged catalyst in the exhaust system but hope it's just the fuel pump. I drove a rabbit for a while that would shudder and then belch out a great big sh**ty cloud of smoke every now and then. The engine rings were all shafted and crud collected in the exhaust until there was too much and it shat the lot out.

edit: sorry I bumped an old thread.

 

[ShoNuff]

Thread necromancy! Gotta love it.

For anyone interested, the car got a new fuel pump AND a new throttle position sensor. It would seem that, somehow, a pin got bent on the sensor (I'm guessing dealer #1 was to thank for that). Ever since then, the car has been rockin' along. Now at 40,000 miles and loving it.

______________________________

Help support this site so it can continue supporting you!

 

[incontrovertible]

My 2009 Genesis V-6 with 24K miles was exhibiting the same engine sputtering the past several days. I brought it to the dealer this morning. He drove it and, as fate would have it, it's not sputtering today. He says he can't find anything wrong.

I told him about similar reports on this site and he said there's nothing he can do since it's not giving him any errror codes. I asked him to call Hyundai service to see if they have any advice. The Hyundai service rep told him there's nothing they can do.

Does anyone have any suggestions as to how to deal with this problem? I don't want to get stuck somewhere as this problem becomes worse.

 

[ShoNuff]

If the dealer hasn't already done so, I would ask them to pull the throttle position sensor and inspect it to see if there is a bent pin.

 

[incontrovertible]

Thanks for the suggestion, SnoNuff.

 

[incontrovertible]

My 2009 V-6 with 25K miles is still hesitating/sputtering at freeway speeds when I (or my cruise control) let up on the throttle. Been to the dealer twice. He says is he can't reproduce it and, without error codes, can't replace any parts. He's reprogrammed the controller twice.

I had him call Hyundai and ask for advice. He says that Hyundai knows nothing about a problem like this happening. I gave him the link to this thread, but he claims these sites are often full of bad information and are not useful.

I'm bringing the car back again in two days for his third try. I'd really appreciate if anyone out there (including Hyundai employees) has any contacts at Hyundai who can help solve this. If so, and you don't want to post the contact, please send me a private message. Thanks.

 

[TomT]

Sounds very similar to my 8/25/ post above. The throttle E sensor was fluctuating replaced throttle position sensor no problems since

 

[crhbobby]

This is EXACTLY what my car has been doing. (I posted about this other day.)

My wife even noticed it yesterday- and she usually is oblivious to things like this.

A friend of mine drove my car 3 weeks ago...and when he gave it back to me, he said - your cruise control is odd...It felt like it kept enginge braking with the cruise. It does it with the cruise or without. Just more noticable with the cruise control when it is decelerating.

I am afraid to even ask the dealer. I think they think I am nit picky. Just not overly friendly anymore.

So you guys think it is just the throttle position sensor?

 

[thom000001]

I'm having EXACT same problem on 09 V6 Tech.....ugh.....and have been to dealer 2 times (useless fools)

Maybe I'll just tear into it this time and find the issue.....i'm guessing TPS as well, but no codes...so dealer won't do crap.

Tom

 

[crhbobby]

One other thing I wanted to note...is that when I start the car in the morning...it revs up and down while it warms up. It did not use to do this. It revs up and down like a vacuum leak.

Bob

 

[homeofstone]

I think others could be correct re: trottle pos. sensor. I had s similar problem on a mazda a few years ago and they(dealer) replaced T P sensor and it fixed the surging.

 

[ShoNuff]

One other thing I wanted to note...is that when I start the car in the morning...it revs up and down while it warms up. It did not use to do this. It revs up and down like a vacuum leak.

Bob

Yup. This (and the cruise control "braking feeling") is exactly what my car was doing. Of course, my dealership said my car had TWO issues - the TPS and the fuel pump. However, I strongly suspect that the fuel pump was never a problem and the dealership just said it was because it didn't want to have to eat the cost of the part.

This seems to be a very concerning pattern developing on the 2009 V6.