Shaking and sputtering idle on startup ??? WTF??

[Aloyouis]

I have a 2012 Avant with 130K miles. It has been shuddering on start up and refusing to start occasionally for a few months but runs great otherwise. The HPFP is leaking a bit and I can smell gas in the oil. It has a P2188 System too Rich at Idle Bank 1 Code stored. I turned of the CEL twice. I am having the dealer replace the HPFP on Friday and changing the oil on Friday. I had another A4 until recently and I can't remember which one I changed the plugs on. To be safe, I will change the plugs on Friday morning before I take it in.

The pump will cost $600 to replace. Am I chasing the wrong thing here? It gets great milage (34mpg on highway, 27 around town). My wife drives this but I drove it yesterday and it does feel sluggish (she would not notice or care).

Thoughts?

[keeva381]

Hey guys - I have 2011 with 118,000 miles on it. I’m having ROUGH start ups with sputtering when cold in the mornings. I step on the gas and the sputtering is worse. It lasts for about 10 seconds and then goes away.

I brought it in for repair and they told me it was bad fuel (too much ethanol in it). Cost me $500 to replace some filters and drain the fuel (they removed the entire back seat). A week later and the problem was back again with engine light on.

Here are the “original” codes they found:

MULTIPLE CODES PRESENT.

P2279-LEAN AIR INTAKE SYSTEM, P2178-TOO RICH OFF IDLE,
P0100-MASS AIR SUPPLY VOLTAGE, P0301,0302,0304 MISFIRES.

FOUND PLUG FOR MAF NOT PLUGED IN ALL THE WAY. CORRECTED.

FOUND BREATHER VALVE LEAKING. REPLACE.

FOUND FUEL IN VEHICLE HAS EXCESSIVE ETHENOL CAUSING MISFIRES.

RECOMMEND DRAINING FUEL TANK AND FILL UP WITH TOP TEIR FUEL ONLY.
DRAIN BAD FUEL FROM FUEL TANK.

I’m now throwing the following codes (this is AFTER all of the work done above):

P2188: System too rich at idle

P2178: System too rich off idle

No idea the difference with these 2 codes. Any suggestions on next steps? I keep up with my maintenance and replace spark plugs every 40K so I doubt it’s an issue with them. I just see a lot of commentary on this thread with replacing the manifold and while I’m not that great with cars it seems pricey (just sounds pricey). I’m calling the shop this morning but it would be great if anyone has any thoughts?

I’m also thinking I paid for a fuel cleaning service for nothing!

[keeva381]

Just a follow up - shop said I need 4 new injectors (too much carbon to clean them - which I've never had done before) and 4 new spark plugs. I guess reasonable at 118,000 miles? $500 for parts and $500 for labor. So this "sputtering" caused me $1,000.

[NYDCB]

Carbon Cleaning is your friends folks. Don't put that off! I paid 740 for a CC just last week. Runs like a new car!

[keeva381]

Carbon Cleaning is your friends folks. Don't put that off! I paid 740 for a CC just last week. Runs like a new car!

So you paid $740 for carbon cleaning or injector replacements? I'm just trying to figure out if I got a decent deal paying $1,000 for injector and spark plug replacements (vs cleaning)?

[ccoaston]

740?!?! for a carbon clean. Really

[keeva381]

Just a follow up - shop said I need 4 new injectors (too much carbon to clean them - which I've never had done before) and 4 new spark plugs. I guess reasonable at 118,000 miles? $500 for parts and $500 for labor. So this "sputtering" caused me $1,000.

Picked up the car yesterday. It's a manual transmission. I stalled out 2-3 times at stop lights. Something with the gas wasn't right, but overall the engine did feel smoother. I figured maybe I just need to adjust how I let off the clutch with the new injectors. Low and behold, the engine light came on AGAIN this morning. It's throwing the same codes too (too rich off idle).

Back to the friggin' shop I go....

[bradthoc]

Just a follow up - shop said I need 4 new injectors (too much carbon to clean them - which I've never had done before) and 4 new spark plugs. I guess reasonable at 118,000 miles? $500 for parts and $500 for labor. So this "sputtering" caused me $1,000.

I thought my dealer mentioned the warranty on injectors was extended to 120,000 miles. Was your need to replace them unrelated?

[keeva381]

I thought my dealer mentioned the warranty on injectors was extended to 120,000 miles. Was your need to replace them unrelated?

You are EXACTLY correct. Wish I had your post about 3 days ago. Would've saved me $1,000. Just spoke with an Audi dealership and they confirmed my VIN is part of the extended warranty. I'm going to call Audi customer service to see if there is anything they can do. Not holding my breath though.

[socoa4avant]

Turned out be an aging O2 sensor for me. Upstream of course.

I had already swapped coils, plugs, injectors battery, decarb on valves and replaced entire intake piping system with factory unit. My codes were random misfire, fuel rail pressure too low and misfire in cylinder 4- i had a fouled plug because of the leaking injector. Either way, new Bosch OE oxgyen sensor got put in Saturday and all of my cold start, 1/2 tank or less hesitation issues are gone.

Fingers crossed thats it. OP, you might wanna run some tests on your upstream O2 sensor.


Sent from my iPhone using Tapatalk

How long have you gone without the rough idle issue since replacing your upstream O2 sensor?

[flowhigh]

FOUND FUEL IN VEHICLE HAS EXCESSIVE ETHENOL CAUSING MISFIRES.

RECOMMEND DRAINING FUEL TANK AND FILL UP WITH TOP TEIR FUEL ONLY.
DRAIN BAD FUEL FROM FUEL TANK.[/B]

Where you using E85?

[socoa4avant]

I am happy to say after replacing my HPFP i am over a month with zero issues. Before replacing it was a daily occurence that I would have idle or hesitation or rough idle issues.

[AutoRacer100]

My car 2010 with 39k miles had a rough idle at startup yesterday morning and this morning. Both days are humid with temperature past 80F around 7 AM in the morning and 95F during the day.

I had the similar rough idle at startup a few years ago. So the high pressure fuel pump is on its way out?

[AbsolutelyMitch]

My car 2010 with 39k miles had a rough idle at startup yesterday morning and this morning. Both days are humid with temperature past 80F around 7 AM in the morning and 95F during the day.

I had the similar rough idle at startup a few years ago. So the high pressure fuel pump is on its way out?

Mine (b8.5 allroad) had a rough idle and start a few times, didn't think much about it as it was super warm and humid out. 5 minutes away from the house and the EPC light came on, rough/shakey vibrations from the motor and the car shut off. 29k miles on the car, roadside assistance came and dealer fixed issue by replacing a bad injector and spark plug in cycl3 (have CPO warranty). Unbelievable that a motor with so little miles has an issue like this.

When getting on throttle I can feel some minimal hesitations and I'm thinking of replacing the spark plugs myself. Weird thing is, the hesitations are sort of... random.

[treginginco]

I developed a rough idle about 10k miles ago. A bad coil pack was found. Replaced and problem gone.


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[Timmyk1993]

Im having the same issues

[allroadstomtl]

my wifes 2012 a4 avant has 102k kms, am here in south fla for the winter months. I usually fill up at costco, one morning I had trouble starting and after two tries it started. This went on for a week so I went to the dealer in Coral Springs. He undid the gas cap pointed to the inside rubber ring showed it was sweating. He said to change to Shell V power or Mobil. Starting got better after three fill ups but now its acting up again.
Are my injectors clogged?
Should I add a cleaner to the tank ?
Will this do the trick?

[vdubjetta02]

Shaking and stuttering is also a sign of a bad Coil Pack.

It could be bad coil pack, bad spark plugs, fuel injectors.

I switch my spark plugs about every 15,000 miles (Since I am stage 2) and I change coil packs about every 50,000 miles as preventative maintenance. Never had a fuel injector problem on my A4's before so I am unsure if it sparks the same symptoms


*I am on my 3rd 2.0t and I have owned 1 1.8t.... so (4) 4 cylinder turbos from VW/AUDI

[socoa4avant]

99.5% chance it is HPFP...I went thru this for months before I replaced the pump and all has been good since...15k miles and going strong

[allroadstomtl]

my issue is only at startup and once it running that sputtering stops.

Also anyone know which indie dealer can i see here in the coral springs, boca, deerfield bch area.

[auditd0rk]

Similar issue here (~97K miles) with long cranks, sputtering right on startup, and even a few stalls when attempting to start. Only code thrown was P2188 (system too rich at idle). Did some logging to see fuel pressure was dropping and even sent out oil for analysis -- fuel dilution was 4.5% (yikes). Ruled out a leaking injector (plugs dry when pulled). Car at the shop now having new HPFP installed. Also hoping that addresses some oil consumption I noticed around same time the startup issues appeared (compression test came back fine; iron level in oil in the green). Just had timing chain tensioner and chain replaced -- been an expensive few months.

[snolvr]

Similar issue here (~97K miles) with long cranks, sputtering right on startup, and even a few stalls when attempting to start. Only code thrown was P2188 (system too rich at idle). Did some logging to see fuel pressure was dropping and even sent out oil for analysis -- fuel dilution was 4.5% (yikes). Ruled out a leaking injector (plugs dry when pulled). Car at the shop now having new HPFP installed. Also hoping that addresses some oil consumption I noticed around same time the startup issues appeared (compression test came back fine; iron level in oil in the green). Just had timing chain tensioner and chain replaced -- been an expensive few months.

Did the new HPFP correct the long cranks, sputtering at idle on startup? Having the same issues as so many in this thread. It's only happening occasionally but I think the HPFP is on its way out.

[Docter]

Matt, your problem is not the problem we are describing in our thread. but i'll be happy to try and help you out. does your car still shake violently at 800rpm? if not, im guessing your motor mounts are starting to go

Sorry to bring this back up but im having this issue but on hot or cold. the idle dips to 850 ish where it's rough then back up to 900 ish where it idles smooth. this happened on the same day after i got a low oil pressure warning. I confirmed 14psi at warm idle with a mechanical gauge. The oil pressure would get as low as 8psi when the idle dipped and would sometimes never recover to 14psi but hang around 10-12psi. idk if this is related either but im getting this strange barking from around the throttle body/intake manifold flap actuator. you are saying this dip in rpms could be from a cracked or broken intake manifold?

[NitroViper]

Sorry to bring this back up but im having this issue but on hot or cold. the idle dips to 850 ish where it's rough then back up to 900 ish where it idles smooth. this happened on the same day after i got a low oil pressure warning. I confirmed 14psi at warm idle with a mechanical gauge. The oil pressure would get as low as 8psi when the idle dipped and would sometimes never recover to 14psi but hang around 10-12psi. idk if this is related either but im getting this strange barking from around the throttle body/intake manifold flap actuator. you are saying this dip in rpms could be from a cracked or broken intake manifold?

Find my post about cold starts.

[Docter]

Find my post about cold starts.

well it didnt happen today on a cold start but it was happening on a warm engine. and im having a hard time searching through your profile and finding the post.