Hesitation or loss of power at partial throttle in 1st and 2nd?

[pseudosuit]

Car is a 20th, 1.8t 6-speed.

I noticed something the other day that is happening occasionally on acceleration. At partial throttle, usually pulling away from a light or stop sign, I get this weird hesitation. It only happens at partial throttle and usually only in first, sometimes in second. As the RPMs increase up to around 3k, it's as if I lose power for a second. You can feel the car stop accelerating for a second, then it begins to pull again.

If it's under heavy acceleration it never happens. It doesn't feel like the clutch slipping, more like the motor hesitating, but there's no noises or missing or anything like that. The RPMs don't jump up or anything. It's like for a second it's making no power, then it comes back.

Anyone experience anything like this. Anything I should check? Thanks for any help.

[SRJetta]

Check your coil pack?

J

[LSinLV]

is your ASR warning lighting up/flashing when this happens??

[hipsiguy]

Quote, originally posted by LSinLV »

is your ASR warning lighting up/flashing when this happens??

??

[LSinLV]

Quote, originally posted by hipsiguy »

??

if you see that dash warning light flashing, that means you are losing traction and the ASR system has throttled back the motor, and applied braking to stop/minimize the traction loss. some people new to the MKIV are not aware of this, and don't realize the car is doing what it was programmed to do.

if this is the case, be more smooth on the throttle, or just turn the ASR off.

[pseudosuit]

It's not ASR because I have it disabled through vagcom. It did it before that however, with ASR on or off. It's definitely not the traction control. And we're talking very partial throttle here, like if you were pulling away from stop and trying not not spill your coffee. No chance of wheel spin.


Modified by pseudosuit at 10:26 AM 2-29-2008

[Warriv04]

I have a similar situation, but I do notice a difference in exhause note, it gets quite a bit louder and seems to bog, but only like he is saying at around 3K and is only evident for about 200-300 RPM. No ASR lights, and happens almost everyday when it is cold.

[pseudosuit]

Quote, originally posted by Warriv04 »

I have a similar situation, but I do notice a difference in exhause note, it gets quite a bit louder and seems to bog, but only like he is saying at around 3K and is only evident for about 200-300 RPM. No ASR lights, and happens almost everyday when it is cold.

Yup, almost exactly like that. It has been very cold here, but it seems to do it when the car is warmed up also.

So you guys think it could be coil packs? There's no CEL and no codes when I scan the car.

[LSinLV]

if the coilpacks or ignition was the issue you WOULD have a CEL.....have you scanned to see if there are any "35-10" intermittant codes in memory???

if not, then I'd say you need to start using measuring blocks to verify that all sensors are within spec....FAQ's/DIY's and the VAGCOM Forum have good info on these tests.

[pseudosuit]

Only stored code is a intermittent short to ground on a the driver's power window switch. I guess I'll just wait until I actually get a CEL. Maybe it'll clear up when the weather gets nicer. I hate winter.

[Warriv04]

Im bankin on it having somethin to do with my old sparkplugs, 57K on them, but thats just a thought... I guess ill have to start accelerating harder.... we all hate doing that...

[AE_3893]

i've been having the same issue at ~59,000mi. I replaced all sparkplugs, put new Hitatchi Style Coils, new fuel filter, Green Top Coolant Sensor, cleaned IAT sensor and MAF, and i am still getting it occasionally. Next thing on the list is Fuel Treatment to clean-up the injectors and valves and cleaning the MAP sensor. it's getting pretty annoying i'm almost wondering if it is weather related also.

[pseudosuit]

bumpage for some more input

[TheWolfsburg]

Experienced the same thing, with CEL... random misfire on piston #1. As you drive the car a little more it stops and some times it just keeps doing in first gear. Nearly positive its a bad coil. Probably the solution to yours too.

[VW1.8Tsunami]

bump because I have the EXACT same problem as the OP...I have a CEL but its for the rear o2 sensor (had it scanned). Mine has been doing it since summer.

[gen2fanatic]

Also experiencing a similar problem. Seems to loose a very little bit of power when slowing down to slower traffic. I throw it in 2nd to start moving with traffic, and seems to loose very little power for a second, then picks back up...

[pseudosuit]

Yup, that's it for sure. Well it looks like I might do plugs and coil packs when spring comes around CEL or not. How much do these coil packs run?

[GTIMike1.8T]

mine is doing the exact same. More so when its cold but even more when its warm. I have noticed a quick fix is plugs. Also may want to see if you have a vac leak. Im gonna try coils and a green top too to see what happens. Anyway if you find a fix before me let me know.

[pseudosuit]

Will do. I think my vacs good or so the boost gauge says. I don't know how accurate that is though. I'll probably just start replacing stuff. Even if it doesn't fix it I'll still feel better. hehe

[TheWolfsburg]

I think your looking at about $100 for the coils $20-30 for the plugs.

[De V ianT]

i have the same thing happening ... but i notice that if you nurse the clutch a little more in those gears in slow acceleration ... it stops ... well i'll have to do coils and plugs too i guess .... ::shrugs::

[GTIMike1.8T]

I fixed mine, decided to get off my ass and change the oil and what not and looked and saw a slight tear in my DV hose going back into the intake. Replaced the hose and yup that was the deal. Even fixed my rough idle.

[butterface]

winter gas FTL.

[gen2fanatic]

Quote, originally posted by GTIMike1.8T »

I fixed mine, decided to get off my ass and change the oil and what not and looked and saw a slight tear in my DV hose going back into the intake. Replaced the hose and yup that was the deal. Even fixed my rough idle.

Damn, I was just under there today. lol Ill check another time.

And when you talk about a rough idle, is yours doing it at every idle, or just when you start it up and it idles rough within the 3-5 minutes after startup?

[Hoxmarch]

Same problem as the OP,
was going to post about it, but yay for finding this first..

It's weird, because it only happens on partial throttle, not WOT..
and it doesnt happen every time, probably like 1/4 or 1/5 times from 0.

Some days it doesnt even happen at all..

Things to check:
coil packs
DV hose
vac

[The J]

Mine has been doing the same thing for over a year.

I've had it back at the dealer while the car was under warranty and reported this 3 times... they could never replicate the problem, which is the response I'd expect from them.

Like posted above, it happens every 1 out of 4 or 5 times, the car just stumbles for a second. No codes or fault codes.

It's not my air filter, coils, plugs, oil, coolant. All those are clean or new. I recently had a coilpack fail so I replaced all 4 and replaced the overboost valve that was throwing intermittent fault codes. I will check the DV hose tomorrow morning and see if there are any leaks.

This is terribly frustrating. Could there be any connection between the ecu and drive by wire throttle?

[Mine's an 03 AWP 1.8T 5 Speed]


Modified by The J at 6:26 AM 3-7-2008

[No6 Ripper]

I had the same problem as the OP since I had my car until I got it chipped, now it never does it. It almost felt like a surging sort of issue, even though it would happen when the rev's were real low and no boost was made. It made me come to the conclusion that it could've been something with the stock ecu program...or just a crazy coincidence. Either way, since I've been chipped the problem has completely disappeared.

[AE_3893]

I scanned the car again recently and got the codes P0135, P0171. These point in the direction of the pre-cat O2 sensor and the MAF. When i get back in a week i am going to replace the Pre-Cat O2 sensor and see if that fixes it. If not the MAF will be replaced along with a throttle body cleaning

[The J]

The more I think about it, the more it seems to me like some of the electrical gremlins that plague these cars. From my experience, outside temp and humidity, engine temp, condition of plugs, oil, coils, have had absolutely no effect on this.

It really may be a bad spot in the ECU maps, where a certain throttle input + MAP reading makes it stutter for a second. Frustrating!

[GTIMike1.8T]

Quote, originally posted by gen2fanatic »

Damn, I was just under there today. lol Ill check another time. And when you talk about a rough idle, is yours doing it at every idle, or just when you start it up and it idles rough within the 3-5 minutes after startup?

Mine would idle like garbage the whole time it was on. Im talking 3-400 rpm increase and decrease. Sometimes it would get so low in the rpms my battery light would come on. But now its all good after replacing the hose.

[The J]

Quote, originally posted by GTIMike1.8T »

I fixed mine, decided to get off my ass and change the oil and what not and looked and saw a slight tear in my DV hose going back into the intake. Replaced the hose and yup that was the deal. Even fixed my rough idle.

Mike,
How big of a tear did you have in the DV hose? I checked mine carefully yesterday and didn't see any tears, but I also didn't remove the hose completely. And what part of the hose had the tear?

On a side note, I pulled my ECU last night, plugged it back in, turned key to ON for 3 mins as it says in the APR instructions for throttle adaptation. This morning the car did not hesitate once and I have a ton of lights and stop signs to try it out. Weird.

I will update this thread if/when it returns.

[By the way, is the key ON for 3 mins for throttle adaptation only for chipped ECUs or is this for all ECUs?]

[The J]

Had 2 slight hesitations this morning. But they were nothing compared to the noticeable surge I have been getting though. This was a mild but smooth hesitation.

[ruetzal]

yep I have the same exact (I mean exact thing happen to me) My best guess since I did change the plugs and my coilpacks are fine (when coilpacks go you can feel the miss) the only thing I can think of that may need looking at is the drive by wire. I think mine needs to be cleaned and re-adjusted. That is my best guess and my cousin had this same thing happen to him on his gti and after he had it chipped it magically disappeared for good..Thats why I am just going to wait until I get mine chipped to bother with any fixes for the time being.

[driver bob]

Same issue on a AWP 1.8T.

Really slight hesitation around 2,300-2,400 rpm, not all the time but sometimes.

It always seems to happen when I'm going light on the throttle.

I'd just put it down to the turbo starting to spool up and there not being enough power fed in to compensate. (But I'm the first to admit I know sweet FA about how it works in reality).

My solution: give it more gas in first and second.

[wishihada18t]

i have the same issue but with a 2.0l.

1st and 2nd gear at light throttle at around 3000 rpm it seems to make less power for a split secound then pick up again. it doesnt feel like a cylinder is missing it just not making the power its supposed to.

I have a newer coil, wires and plug and oil change .