Lean Fuel Issues after 4k rpm on Revo Stage 2+ Ed30

[illyun]

Sorry for the repost - RR thought it might be useful as a separate topic here - I'll update this thread as work to diagnose the issue on my Ed30 progresses. 


Well I had my car remapped to Stage 2 back in November last year and it has been running fine.  The day before Santa Pod on the 31st Jan, I went to Northampton Motorsport as recommended by Revo because I was in a hurry to get Stage 2+ for RWYB and I had not been able to get to JKM in time the day before.  Anyway, they put the code on and I went happily thinking I had approx 350bhp... though it didn't seem much different.  My Santa Pod times weren't that good - best was 13.67s 1/4 mile, but that was put down to having a full tank of fuel, a Revo boost setting of only 5 and only 1 go on the strip - and for the first time.  Plus the front wheels were at 1.6mm so I thought the time would be better when I these shortcomings had been resolved next time. 

I was getting my boost gauge fitted by JKM early this month and thought I should also get the car settings sorted and the car RR'd to make sure everything was running as it should be.  I spent a whole day at JKM and Keith told me that the car was having problems.  It had been dyno'd at 321bhp back in November when I had Stage 2 installed and despite now having Stage 2+, it was still making 320bhp?!    Also, boost was set to 9 and not 5 as I had requested.  Keith initially suspected that the code hadn't been installed correctly, but when he reinstalled Stage 2+ on, it made no difference. 

I had to rebook the car in and Keith had a few discussions with Revo HQ who were/are adament that the code is fine and that there was/is an issue with the car. 

I went back to JKM on Thursday 12th and left the car overnight.  Keith went through a lot of things and found that there was an issue with lean fuel after 4k rpm  which is potentially serious as it can damage the engine - although I am not sure exactly how and why.  Basically, Keith did all the usual checks and tests, checking for vacuum leaks and even replacing the fuel pump, fuel filter etc... but couldn't find the problem in that time.  Oh, he had to fit a Carbon Fibre bonnet at the same time which took some time up    Priorities and all that    He produced a report for me that describes the work carried out which I have inserted below.   

The lean fuel issue disappears for lower boost settings (and therefore lower power) and the car is currently running safely at 255bhp, boost 1 on Stage 2+ software - basically on stock settings although the power isn't stock due to the exhaust, APR fuel pump etc...

 

I recieved an e-mail from Keith last Monday and he suspects a certain area in the data output as he kindly looked through the data produced over the weekend.  I had the car booked in for Thursday and Friday just gone but unfortunately for Keith, his father-in-law passed away and he was not at JKM during those days.  The car is booked for next Wednesday and Thursday now and I am hoping the issue is sorted in time for the GTI Spring Festival     

[KRL]

Do you have any data showing what your AFR is currently running at?

[KRL]

Also here are my other comments posted on the other thread:

I do agree that it sounds like a HW problem and it is likely you have a leak somewhere.  Have you checked the condition of your PCV?

If you have VCDS could you post some logs up?  I can advise which blocks to monitot etc if need be.

[KRL]

Regarding the P2177 fault code you are seeing it could be any of the following:

  18609/P2177/008567 - Bank 1; System Too Lean off Idle: Upper Limit Exceeded
Possible Symptoms

    * Malfunction Indicator Ligh (MIL) active

Possible Causes

    * Fuel Pump (G6) faulty
    * Mass Air Flow (MAF) Sensor (G70) faulty
    * Intake System leaking
    * Exhaust System leaking

Possible Solutions

    * Check Mass Air Flow (MAF) Sensor (G70)
    * Check Fuel Pump (G6)
    * Check Fuel Injectors
    * Check Intake System
    * Check Exhaust System

Are you seeing any other fault codes?

[illyun]

Thanks for the advice KRL.  The fuel pump was replaced and exhaust and intake checked and ruled out - although there could be a possibility that something was missed out during the checks, but JKM say they were very thoroughly checked so it seems unlikely.  But as you say, as the problem is getting worse, it points to a physical leak or condition that is getting bigger/worse.  The MAF 'item' - not sure what they are referring to here - was replaced and also the MAF was disconnected but made no difference so thats the possible causes checked.  Similar checks were done with the injectors... Keith told me that all the usual suspects were checked and ruled out.  The fuel is running VERY lean at the top boost setting and 5.5k rpm and I saw a huge spike in difference between expected and received fuel.  There are no other fault codes so it is a strange one.  Keith has said that he has seen some suspect readings that are pointing towards something in the logs but he didn't elaborate in his pm - I'll find out on Wednesday/Thursday next week. 

I do have VCDS, but it would be an issue taking logs when driving for two reasons...

1.  I don't know anyone in Ipswich who could competently sit with me in the vehicle and operate the VCDS while I drove the car and starting/stopping it while driving by myself is dangerous - I suppose I could do it in neutral, but I'm not sure whether this would be the same.

2. I would have to go towards redline in 3rd and 4th gears and this means speeds in excess of 120mph which is illegal... so again a bit stuck there....

Am I completely missing the point regarding taking logs?  Is there an easier/more feasible way?

[illyun]

By the way, in early March, when I took the car to JKM, the fuel pressure requested was 130bar but it was only getting 118bar tops...

[Hedge]

Am I completely missing the point regarding taking logs?  Is there an easier/more feasible way?

It is possible to do it alone. 3rd gear from low rpm to the red line(ish). Each time you do a run just press the space bar and it puts a marker in the margin. When you have finished you can save them and chop them up into individual runs.
I can show you if you like.

Personally speaking though as Keith has started the process I would leave him to finish.
I am sure he would send you the logs if you asked.

[illyun]

Am I completely missing the point regarding taking logs?  Is there an easier/more feasible way?

It is possible to do it alone. 3rd gear from low rpm to the red line(ish). Each time you do a run just press the space bar and it puts a marker in the margin. When you have finished you can save them and chop them up into individual runs.
I can show you if you like.

Personally speaking though as Keith has started the process I would leave him to finish.
I am sure he would send you the logs if you asked.

Thanks for that tip.. didn't know you could do that.   

I am inclined to let Keith try and resolve it this coming week.  If we still can't get to the bottom, then I'll see whether Revo can help and scream on this forum as loud as possible - hoping someone can help. But I am confident it will be resolved this week   

Well I hope so...

[john_o]

illyun :

first off really appreciate you taking the time to share all this info 
I know first hand how frustrating and time consuming these issues can be 
Im confident JKM will resolve it as they seem thorough and the best people to have on the case 

my prob irrelevant musings ........
Have you tried flashing the car back to Stage2 and seeing how it runs on that SW (just to rule out SW issues?)
Im surprised the car allows the boost/AFR to get into dangerous lean territory before backing off, usually its over protective?
Is your cam/follower ok?
Im surprised the hpfp logs ok while the condition is happening!
if its a low pressure problem the hp rail pressure would drop as it cant be fed enough?
Is it always the same rpm the afr leans out?
is there any possible fuel line damage under the car?

hope it gets sorted soon and keep us updated
search golfmkv.com as theres plenty of info on their for REVO logs (actual vs requested) and also the fault code.
fingers crossed
JohnO

[illyun]

Didn't know this modding lark would turn me into a 

[KRL]

.  The MAF 'item' - not sure what they are referring to here - was replaced and also the MAF was disconnected but made no difference so thats the possible causes checked.

I assume the MAF item means the actual physical MAF sensor was replaced.

The fuel is running VERY lean at the top boost setting and 5.5k rpm and I saw a huge spike in difference between expected and received fuel.

Do you have actual figures as to how lean the AFR is?  The ECU should have some protection mapping built in which does not allow the AFR to go beyond a specific value, I believe with a REVO setting of fuel 9 this means minimum AFR requested of 12.1 IIRC.

There are no other fault codes so it is a strange one.  Keith has said that he has seen some suspect readings that are pointing towards something in the logs but he didn't elaborate in his pm - I'll find out on Wednesday/Thursday next week. 

Sounds like you are in good hands with JKM and I agree that you should use them as for your troubleshooting for now.  Please keep us all posted with the findings though.

1.  I don't know anyone in Ipswich who could competently sit with me in the vehicle and operate the VCDS while I drove the car and starting/stopping it while driving by myself is dangerous - I suppose I could do it in neutral, but I'm not sure whether this would be the same.

3rd gear runs are possible to do yourself if you set up the VCDS logging before hand and then just leave your laptop sat in the passenger footwell while doing the runs, then you can post process the data later on.

There would be no point in doing the runs in neutral as there would not be any load on the engine.  Also I don’t think you can rev the DSG in neutral past about 3.5k anyway!

Also I live in Bury St Edmunds and am willing to help if you ever need it.

2. I would have to go towards redline in 3rd and 4th gears and this means speeds in excess of 120mph which is illegal... so again a bit stuck there....

Redline in 3rd gear will take you to about 83 MPG.  4th gear on public roads = no go.  The best place to do logging would be on a long straight private road, the second best place would be on a dyno.

Am I completely missing the point regarding taking logs?  Is there an easier/more feasible way?

Hopefully answered that above.

[KRL]

Personally speaking though as Keith has started the process I would leave him to finish.
I am sure he would send you the logs if you asked.

Agree with this.  I think the logs would be very interesting for all to see and hopefully we could learn from them as well.

[KRL]

Im surprised the car allows the boost/AFR to get into dangerous lean territory before backing off, usually its over protective?

Yes there should be some protection mapping built in.  I have heard ramblings on the US forums saying that REVO may have disabled this protection mapping in their remaps, whether this is true or not I am unsure.

[john_o]

indeed in some old posts it looked as if it was disabled but newer posts/logs indicate that the protection map was present.
not sure what to think 

[WhiteGTI]

Im surprised the car allows the boost/AFR to get into dangerous lean territory before backing off, usually its over protective?

Yes there should be some protection mapping built in.  I have heard ramblings on the US forums saying that REVO may have disabled this protection mapping in their remaps, whether this is true or not I am unsure.

indeed in some old posts it looked as if it was disabled but newer posts/logs indicate that the protection map was present.
not sure what to think 

This concerns me ....