Intermittent hard or no start on 4.0T S6 S7 RS7- possibly solved

**pez81** · 12-01-2018 01:55 PM

I'm about 9 days in with no start up issues. For once I'm happy it's cold

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**Hofahome** · 12-01-2018 02:02 PM

Originally Posted by pez81

I'm about 9 days in with no start up issues. For once I'm happy it's cold

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Mine has been better lately too. started up great the last 2 days.
Do me a favor and smell your oil cap after going for a drive.

**pez81** · 12-01-2018 02:05 PM

Originally Posted by Hofahome

Mine has been better lately too. started up great the last 2 days.
Do me a favor and smell your oil cap after going for a drive.

Yeah I was gonna do that after I read your post. One thing I've been doing differently is when filling her up not try and add extra. I always push it until it literally keeps clicking off.

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**brad281** · 12-03-2018 08:57 PM

Originally Posted by pez81

Yeah I was gonna do that after I read your post. One thing I've been doing differently is when filling her up not try and add extra. I always push it until it literally keeps clicking off.

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I have never added extra fuel to mine once the pump clicked off.

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**Hofahome** · 12-03-2018 08:55 PM

Update: I took my car in to get this looked at. He agreed my car drives fine otherwise. His plan is to check for rail pressure difference after leaving it to cool off.

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**Hofahome** · 12-04-2018 11:14 PM

New update. My mechanic said he is 95% sure it is from leaking injectors, although hard to say which one or ones at this point. The car is loosing rail pressure and is not keeping up with what spec should be after turning the car off for set period of time. He is doubtful that it is bad hpfp given fuel smell when starting up, meaning cyl are flooded.
It is engine out. A joy for everyone involved.
We agreed on new plugs all around although mine are relatively new.
Told him about the turbo oil strainer tsb and since it was not done at time of prior turbo install we agreed to do this along with the pcv module.

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**Cris_OO7** · 12-05-2018 05:15 AM

Originally Posted by Hofahome

New update. My mechanic said he is 95% sure it is from leaking injectors, although hard to say which one or ones at this point. The car is loosing rail pressure and is not keeping up with what spec should be after turning the car off for set period of time. He is doubtful that it is bad hpfp given fuel smell when starting up, meaning cyl are flooded.
It is engine out. A joy for everyone involved.
We agreed on new plugs all around although mine are relatively new.
Told him about the turbo oil strainer tsb and since it was not done at time of prior turbo install we agreed to do this along with the pcv module.

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That suks sorry to hear that. Since they going to be in there curious to see how clean the intake valves are and if any cleaning is needed. How many miles does it have?

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**JD S4** · 12-05-2018 05:44 AM

Originally Posted by Hofahome

New update. My mechanic said he is 95% sure it is from leaking injectors, although hard to say which one or ones at this point. The car is loosing rail pressure and is not keeping up with what spec should be after turning the car off for set period of time. He is doubtful that it is bad hpfp given fuel smell when starting up, meaning cyl are flooded.
It is engine out. A joy for everyone involved.
We agreed on new plugs all around although mine are relatively new.
Told him about the turbo oil strainer tsb and since it was not done at time of prior turbo install we agreed to do this along with the pcv module.

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Dude. Brutal. Sorry man. If you didn’t have bad luck, you’d have no luck at all

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**pez81** · 12-04-2018 11:28 PM

Oh that sucks. Hope it at least fixes the issue for you. I'm still confused why mine hasn't done it for 2 weeks.

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**Hofahome** · 12-11-2018 09:40 AM

The warranty approved injector replacement and we are doing them all since we couldnot pinpoint which one. We are also doing intake valve cleaning since it is out.
My mechanic said in the future he wants me to buy Japanese cars only lol

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**brad281** · 12-11-2018 09:48 AM

Originally Posted by Hofahome

The warranty approved injector replacement and we are doing them all since we couldnot pinpoint which one. We are also doing intake valve cleaning since it is out.
My mechanic said in the future he wants me to buy Japanese cars only lol

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Warranty cover the whole thing?

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**Hofahome** · 12-11-2018 10:54 AM

Originally Posted by brad281

Warranty cover the whole thing?

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Not the valve cleaning or pcv replacement/oil screen but yes to everything else.

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**brad281** · 12-11-2018 10:56 AM

Originally Posted by Hofahome

Not the valve cleaning or pcv replacement/oil screen but yes to everything else.

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I'm sure the labor is greatly reduced for those repairs with the engine already being out. Hope that corrects your issue.

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**15 Phantom S6** · 12-12-2018 07:01 AM

Hard to fully tell by the picture, but those valves appear to be pretty "carboned" up.. Is it possible that the carboned up valves is the cause of your issues? What is the mileage of your ride?

**Hofahome** · 12-12-2018 05:36 PM

Originally Posted by 15 Phantom S6

Hard to fully tell by the picture, but those valves appear to be pretty "carboned" up.. Is it possible that the carboned up valves is the cause of your issues? What is the mileage of your ride?

I have 72k miles. The valves are not likely to be the issue since we saw that the rail pressure could not hold steady after turning the car off.

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**MKEAudi** · 12-12-2018 07:26 PM

Originally Posted by 15 Phantom S6

Hard to fully tell by the picture, but those valves appear to be pretty "carboned" up.. Is it possible that the carboned up valves is the cause of your issues? What is the mileage of your ride?

That's nothing, especially for 72k miles

**russjameson** · 12-18-2018 10:32 AM

hHas anyone gotten any more insight from the Stealership on this.
All they want me to do it come in and let them flash it back to stock and have me pay $270 bucks for the TSP to be performed.
I think that sounds like a waste of $270 bucks for me.

I got my Stage 3 APR reflashed, and still the same, no difference at all.

**Hofahome** · 12-18-2018 09:19 PM

Originally Posted by russjameson

hHas anyone gotten any more insight from the Stealership on this.
All they want me to do it come in and let them flash it back to stock and have me pay $270 bucks for the TSP to be performed.
I think that sounds like a waste of $270 bucks for me.

I got my Stage 3 APR reflashed, and still the same, no difference at all.

Just got my car back tonight. No issues so far but reserving any further judgement until I get a few days in.
$270 seems like a waste. Thats like 2.5 hours labor for a ecu flash...

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**russjameson** · 12-19-2018 05:38 PM

Originally Posted by Hofahome

Just got my car back tonight. No issues so far but reserving any further judgement until I get a few days in.
$270 seems like a waste. Thats like 2.5 hours labor for a ecu flash...

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What did you get done while it was away?
I have a guy that wants me to bring it by so he can mess with it but my daily is down with a blown turbo so I'm driving the S6 around every day cussing at it...alot. He seems to think it's a fuel pump issue. I'll let him poke around for free if he wants. Lol

**Hofahome** · 12-19-2018 07:38 PM

Originally Posted by russjameson

What did you get done while it was away?
I have a guy that wants me to bring it by so he can mess with it but my daily is down with a blown turbo so I'm driving the S6 around every day cussing at it...alot. He seems to think it's a fuel pump issue. I'll let him poke around for free if he wants. Lol

Well my car threw a cel today for both intake runner flaps stuck closed. For my mechanic’s sake I hope it is just an unplugged vacuum line, however I cringe to think that the intake manifolds were reinstalled with the flaps in the “down” position and are getting stuck on the metal dividers when trying to open. The only way I could see to fix this would be engine out again. Ugh.
Car is starting without issue now though.

Does your oil cap smell like gas?

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**JD S4** · 12-19-2018 07:59 PM

Ugh. Awful. Sorry this is happening guys

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**Hofahome** · 12-19-2018 08:11 PM

Originally Posted by JD S4

Ugh. Awful. Sorry this is happening guys

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Hey man thx. ya frustrating to say the least. How is the sq with a tune? I just rode in a coworkers new one and was impressed, although she fucked up and got it in blue.
Gotta get together for a beer again soon. Maybe I'll uber down to you lol.

**aFOURstance** · 12-27-2018 06:44 AM

Did you guys determine that this is due to leaky injectors?

**Hofahome** · 12-27-2018 10:45 AM

Originally Posted by aFOURstance

So I was free of the hard starting issue for about a month, now it’s every other day. Did we determine that this is due to leaky injectors? I’m tired of looking like a fool in the parking lot with an expensive car that won’t start lol

It has not come back for me. You have any codes?

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**aFOURstance** · 12-29-2018 08:49 AM

You guys still having issues?

**wwhan** · 01-03-2019 06:14 PM

Originally Posted by aFOURstance

No CEL, no soft codes via VCDS, no warnings

There is also this 4.0T TSB 204672/4 Oct2017, hard to start, no codes.

**Hofahome** · 01-03-2019 06:55 PM

Originally Posted by wwhan

There is also this 4.0T TSB 204672/4 Oct2017, hard to start, no codes.

Fuck that would have been helpful a month ago to me. But thx for posting here for others.

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**Hofahome** · 01-03-2019 04:33 PM

A bit of an update.
My car was driving great for a few days after the injectors were replaced but then threw cel for closed intake flaps. Do not exceed 4k rpm. Great.

My mechanic knew the flaps were installed correctly so the thought was one of the vacuum lines came off. I took the car in and he tested the lines, all was good. He then tested the vacuum solenoid and no dice. My mechanic is a good friend and he said they didn’t even touch the solenoid during recent service and I believe him. So basically it was just bizarre timing after my recent injector replacement. Turns out there is a tsb for this on our motors fyi.

I miss driving my car...

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**brad281** · 01-03-2019 04:38 PM

Originally Posted by Hofahome

A bit of an update.
My car was driving great for a few days after the injectors were replaced but then threw cel for closed intake flaps. Do not exceed 4k rpm. Great.

My mechanic knew the flaps were installed correctly so the thought was one of the vacuum lines came off. I took the car in and he tested the lines, all was good. He then tested the vacuum solenoid and no dice. My mechanic is a good friend and he said they didn’t even touch the solenoid during recent service and I believe him. So basically it was just bizarre timing after my recent injector replacement. Turns out there is a tsb for this on our motors fyi.

I miss driving my car...

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Damn! Sorry to hear. Easy fix?

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**Hofahome** · 01-03-2019 06:59 PM

Originally Posted by brad281

Damn! Sorry to hear. Easy fix?

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Thx man. Hopefully this thread can help someother poor sap. I honestly dont know yet about the fix.

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**wwhan** · 01-03-2019 09:34 PM

....that would have been helpful a month ago to me. But thx for posting here for others.
......

Well, I did in post #10, the TSB number (204672/4) a month ago (11-09-2018 ): https://www.audizine.com/forum/showt...1#post13383505

"There is a TSB:

TSB 01 17 37 204672/4, October 4, 2017

01 engine sporadically difficult to start - 4.0tfsi

Update ECM software "

**russjameson** · 01-04-2019 03:10 PM

Originally Posted by wwhan

Well, I did in post #10, the TSB number (204672/4) a month ago (11-09-2018 ): https://www.audizine.com/forum/showt...1#post13383505

"There is a TSB:

TSB 01 17 37 204672/4, October 4, 2017

01 engine sporadically difficult to start - 4.0tfsi

Update ECM software "

has anyone gotten this done yet and fixed the issue. This is what I was told will cost $270 and will probably flash me back to stock. I told my APR dealer to be ready for me to come in for a reflash back to stage 3 if and when I get this TSB done.

**Avned** · 02-20-2019 07:01 PM

Mine was solved when the injectors were replaced. My tuner first tried the fuel pumps but that didn't solve the issue. It's been several months now and no more starting issues.

**russjameson** · 03-07-2019 06:36 AM

Originally Posted by Avned

Mine was solved when the injectors were replaced. My tuner first tried the fuel pumps but that didn't solve the issue. It's been several months now and no more starting issues.

Which fuel pumps, the HPFPs in the engine bay?

**Qweklain** · 03-29-2019 05:28 PM

I am having this issue right now. Started about two weeks ago when we started getting temperatures consistently above 40 degrees Fahrenheit. My car runs fine, starts fine cold or shortly after turning it off (within ~20 minutes or less) if warmed up, but if it sits for around 45 minutes or so, or when it has cooled down a bit, it will die as soon as it fires. If I do not hit the gas a bit when it fires, I have to wait at least a minute or two before I can try again because it just cranks after that first pop.

**wwhan** · 03-29-2019 08:46 PM

Another interesting TSB ; https://static.nhtsa.gov/odi/tsbs/20...19940-9999.pdf

“01 15 14 2014753/9 March 9, 2015. Supersedes Technical Service Bulletin Group 01 number 13-09 dated June 21, 2013 for reasons listed below.”

“Supersedes Technical Service Bulletin Group 01 number 13-09 dated June 21, 2013. The use of contaminated gasoline or gasoline with a low content of deposit control additives may result in excessive accumulation of deposits on intake valves, intake manifold, fuel injectors, and combustion chambers, engine running rough after cold start, excessive engine cranking time, hesitations while driving, rough engine idle, Reduced engine performance, and/or Poor fuel economy. Conditions may be severe enough to illuminate the MIL in conjunction with storage of DTCs for misfire, lean fuel system, or air/fuel ratio imbalance in the engine control module. Condition may be caused by use of contaminated gasoline. Condition may be caused by use of gasoline with a low content of deposit control additives.”

“Repair:
Gasoline additive G 001770A2 can be used for removal of existing carbon deposits from:
• Injectors (MPI and FSI engines)
Combustion chambers (MPI and FSI engines)
• Intake valves (MPI engines only)
Mix the additive with gasoline directly in the full fuel tank following the mix ratio. For example, 60 ml per 20 liters gasoline or 120 ml per 10 gallons of gasoline.
Tip: For removal of carbon deposits from intake valves of FSI engines, refer to TSB 2019948.“

**Qweklain** · 04-12-2019 06:51 PM

Originally Posted by Qweklain

I am having this issue right now. Started about two weeks ago when we started getting temperatures consistently above 40 degrees Fahrenheit. My car runs fine, starts fine cold or shortly after turning it off (within ~20 minutes or less) if warmed up, but if it sits for around 45 minutes or so, or when it has cooled down a bit, it will die as soon as it fires. If I do not hit the gas a bit when it fires, I have to wait at least a minute or two before I can try again because it just cranks after that first pop.

Just thought I would update here that I found out I am running the latest version of the ECM which already contains the SVM for TSB 2046724/4 that has a description describing this issue. Obviously I am having the issue with this "fix" already applied, so it is something else.

I am going to be taking off my HPFPs and cleaning them. I am 95% sure the pumps themselves are perfectly fine, just like everyone else here having the issue. I personally think the culprit is the stupid fuel regulator sensor that plugs into our HPFPs that, of course, you cannot buy separately and have to buy a whole damn new pump. If the cleaning does not work, I will probably try to find out what the exact sensor is (Nxx, something like that), find what other vehicles use these pumps, and find some cheap ones to get different sensors.

**Hofahome** · 04-12-2019 09:45 PM

Originally Posted by Qweklain

Just thought I would update here that I found out I am running the latest version of the ECM which already contains the SVM for TSB 2046724/4 that has a description describing this issue. Obviously I am having the issue with this "fix" already applied, so it is something else.

I am going to be taking off my HPFPs and cleaning them. I am 95% sure the pumps themselves are perfectly fine, just like everyone else here having the issue. I personally think the culprit is the stupid fuel regulator sensor that plugs into our HPFPs that, of course, you cannot buy separately and have to buy a whole damn new pump. If the cleaning does not work, I will probably try to find out what the exact sensor is (Nxx, something like that), find what other vehicles use these pumps, and find some cheap ones to get different sensors.

Just an FYI, you can buy the low pressure fuel sensor/regulator (G410) that sits on the driver side hpfp. It is the fuel metering valves cannot be bought separate from the pump. But that is probably not the issue. According to my SA at Audi these pumps tend to fail internally, leaking gas into the valvetrain. Not sure if this is somehow related to injector failure but I bet in some way they are connected.

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**wwhan** · 04-18-2019 05:54 PM

There is another TSB...

TSB 01 Engine sporadically difficult to start - 4.0TFSI
01 19 00 2046724/7 January 11, 2019

"Customer statement:
The engine sporadically does not start after reaching operating temperature and being parked for longer
stationary periods (engine not completely cooled down). However, the starter motor will turn over normally.
The engine sporadically does not start or only after long cranking period then runs rough for a few seconds
(starter motor turns normal).
Workshop findings:
Usually there are no DTCs in the engine control module (ECM), J623 (address word 0001).
Or
Sometimes a DTC about fuel metering system "System too rich" will appear in the engine control module
(ECM), J623 (address word 0001).
Technical Background
Deviation in fuel-air mixture at engine start."

"Service
Perform the following checks:
1. Read the DTC memory of the ECM.
2. Read/assess the measured value with the ODIS measured value identifier IDE09529 "Fuel mass flow
fumigation from engine oil". Warm up the engine at idle speed and observe the above measured value
together with the engine oil temperature. The evaporation process of fuel in the engine oil starts at about
122°F engine oil temperature.
a. If the value of the fuel mass flow is at least intermittently above 75 mg/s, this clearly points to a high fuel
share in the engine oil (over 0.5 l). In this case, the condition is caused by an extreme short distance
operation profile of the customer. We recommend to change the engine oil with filter and to explain the
background to the customer. Update the ECM with SVM code 01A225.
b. If the limit of 75 mg/s is not exceeded and the condition cannot be reproduced, the driving profile of the
customer before the workshop visit may have completely consumed the fuel in the engine oil. In this case,
we also recommend to enquire about the driving profile of the customer for a possible explanation."

"If high pressure fuel pump/pumps are replaced use Service Number 2463, Damage Code 0050."

**Qweklain** · 05-06-2019 08:40 AM

I found a spring and got it in a couple days ago. The good news is the spring is the same as almost every HPFP Audi has used on any of their v8s in the last 10 or more years (there are exceptions I found). Basically, if the spring uses a retainer like the one in the picture in my previous post, it is the same spring. The other spring they use is the one that they use in, for example, their 2.0 TFSI. It does not have a split retainer and the piston itself does not sit on the tappet the way our HPFP springs do.

The bad news is now my car runs better than I can remember when it is cold, but when it is warm enough for the RPM limiter to remove itself (aka go into close loop), the car dies, pretty much will not start and if it does, the idle surges by about 600 RPM, and it misfires constantly. I am pretty sure it is my tune to be honest as I believe the changes that were made to it after the base stage one was applied has now put the amount the ECU can adjust out of its capability, but I am just theorizing with that one at this point. The car does run perfect when it is cold (in open loop) though.