MK5 Golf GTI

All Things Mk5 => How to Guides / Troubleshooting => Topic started by: krisbutler02 on March 14, 2013, 01:59:28 pm

Title: Very lumpy idle
Post by: krisbutler02 on March 14, 2013, 01:59:28 pm
My GTI had the AXX engine in that used to idle like it had lairy cams ,

This engine dropped its thrust bearings so now have a Audi S3 BHZ engine fitted with all the AXX sensors and ancillaries.

This engine does the same, it has a different map now (stage 3 revo K04 file) 

Its so lumpy its not right

I have the forge catch can so no PCV issues, i have checked for air leaks and the vacuum in 0.8 bar at idle.

New iridium plugs , new MAF , APR fuel pump ,New in tank fuel pump.  cam lobe and follower are fine, N80 purge valve works fine. cant find any air leaks , all boost pipework is new / silicone.

Dump valve is sealing and perfect

What else could cause this im kinda stuck now


The idle is around 700-750 RPM
Title: Re: Very lumpy idle
Post by: krisbutler02 on March 14, 2013, 03:20:48 pm
Any ideas how to raise idle in vagcom?
Title: Re: Very lumpy idle
Post by: Hurdy on March 14, 2013, 04:57:56 pm
Have you changed the coilpacks too?
Title: Re: Very lumpy idle
Post by: krisbutler02 on March 14, 2013, 05:16:30 pm
Yes just tried another set of coil packs.

starting to annoy me now haha
Title: Re: Very lumpy idle
Post by: Saintsteve on March 14, 2013, 05:21:02 pm
Any ideas how to raise idle in vagcom?
You can't.

Clogged up intake valves causing low idle?

How many miles has the new engine done in its previous life?? Emmisions test to check for hydrocarbons would indicate coked up cyl.head.?


Title: Re: Very lumpy idle
Post by: krisbutler02 on March 14, 2013, 05:22:03 pm
Cleaned manifold and intake valves just before engine went in.
Title: Re: Very lumpy idle
Post by: Saintsteve on March 14, 2013, 05:23:24 pm
Throttle body?
Title: Re: Very lumpy idle
Post by: krisbutler02 on March 14, 2013, 05:25:04 pm
also cleaned and reset via vag com along with the manifold flaps.

also run super unleaded shell v power always and did put some injector cleaner in too
Title: Re: Very lumpy idle
Post by: Saintsteve on March 14, 2013, 05:50:02 pm
also cleaned and reset via vag com along with the manifold flaps.

also run super unleaded shell v power always and did put some injector cleaner in too

Have you tried running it on the stock map to rule out the remap?

Then I'd look at the bits that don't normally fit the BHZ engine if you've mixed from AXX perhaps?
Title: Re: Very lumpy idle
Post by: krisbutler02 on March 14, 2013, 06:02:07 pm
I have switched the sps to stock and its the same.

the only thing left on the BHZ engine that isnt what i swapped over on the axx is the camshaft sensor. and the injectors

im going to get a new inlet manifold with new thrust sensor.

Thats all i can think of to do next.

Only thing i do wonder is if the single mass flywheel (sachs) would make it idle funny due to the weight difference.
Title: Re: Very lumpy idle
Post by: greygti on March 14, 2013, 09:34:04 pm
Have you checked/replaced the primary o2 sensor ??
Title: Re: Very lumpy idle
Post by: northyracing on March 14, 2013, 09:39:25 pm
I have the same problem on my axx engine and can't find why
Title: Re: Very lumpy idle
Post by: krisbutler02 on March 14, 2013, 09:41:37 pm
Is tha pre cat or post? Funny you should say that as my liquid gauge always reads rich even at wot doesnt go below 14 afr
Title: Re: Very lumpy idle
Post by: vRSAlex on March 15, 2013, 08:05:19 am
14 is lean for wot. Should be 12. 14.7 when cruising.

Have you read the missfire counters and whats your idle fuel trim like?
Title: Re: Very lumpy idle
Post by: krisbutler02 on March 15, 2013, 08:23:42 am
It says missfire dissabled.?

The Liquid gauge is lying vag com logs .77 Lambda

How do i read fuel trims ?
Title: Re: Very lumpy idle
Post by: krisbutler02 on March 15, 2013, 11:47:02 am
says requested 1 lambda at idle and its 1 specified.

Damb cars

Title: Re: Very lumpy idle
Post by: krisbutler02 on March 15, 2013, 04:45:35 pm
Here is a 4th gear run log from today

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fn19%2Fkrisbutler02%2FUntitled.jpg&hash=eb6e170d7f90c5eb19f77c92a281d70a4512be12)
Title: Re: Very lumpy idle
Post by: krisbutler02 on March 15, 2013, 04:47:57 pm
logs on idle

Marker   TIME   Group 1 - Field 0   TIME   Group 2 - Field 2   TIME   Group 2 - Field 3   TIME   Group 14 - Field 2   TIME   Group 31 - Field 0   TIME   Group 31 - Field 1   TIME   Group 32 - Field 0   TIME   Group 32 - Field 1
   STAMP   Engine Speed   STAMP   Injection - Timing   STAMP   Intake Air Mass   STAMP   Misfire - Sum Counter   STAMP   Lambda Sensor - Current Value   STAMP   Lambda Sensor - Specified Value   STAMP   Lambda (Idle) - Self-Adaptation   STAMP   Lambda (Partial) - Self-Adaptation
       /min       ms       g/s                         %       %
   0.64   760   0.78   1.02   0.78   3.64   0.91   0   0   0.98   0   1   0.13   -0.7   0.13   -0.4
   1.63   800   1.76   1.02   1.76   3.17   1.89   0   1.02   1.1   1.02   1   1.14   -0.7   1.14   -0.4
   2.66   760   2.79   1.28   2.79   3.25   2.93   0   2.02   0.95   2.02   1   2.15   -0.7   2.15   -0.4
   3.69   760   3.82   1.02   3.82   3.28   3.96   0   3.05   1.04   3.05   1   3.18   -0.7   3.18   -0.4
   4.72   760   4.85   1.02   4.85   3.61   4.99   0   4.08   0.96   4.08   1   4.21   -0.7   4.21   -0.4
   5.75   720   5.88   1.53   5.88   6.03   6.02   0   5.11   1.02   5.11   1   5.24   -0.7   5.24   -0.4
Title: Re: Very lumpy idle
Post by: vRSAlex on March 15, 2013, 06:03:31 pm
Car needs to be running for a while before the missfire detection becomes enabled.

Trims on 032 look fine.
Title: Re: Very lumpy idle
Post by: greygti on March 15, 2013, 06:31:34 pm
Is tha pre cat or post? Funny you should say that as my liquid gauge always reads rich even at wot doesnt go below 14 afr
Its pre-cat mate, £135 from TPS, if this is the problem of course
Title: Re: Very lumpy idle
Post by: krisbutler02 on March 15, 2013, 08:41:24 pm
Need somone to have a look ill get a video tomorrow sounds like a rally car idleing . 
Title: Re: Very lumpy idle
Post by: camfollower on March 15, 2013, 08:55:34 pm
Was that log taken in 4th gear at WOT?

At 4.2k your making about 191HP, less than a Stage 1 K03 - however you then go on to make a full 307HP at max revs (estimated). :confused:
Title: Re: Very lumpy idle
Post by: krisbutler02 on March 15, 2013, 09:22:51 pm
Yes thats at WOT it does seem low but i havent a clue why.

Any ideas ?
Title: Re: Very lumpy idle
Post by: krisbutler02 on March 16, 2013, 06:56:59 am
Could be due to the fluttering boost
Title: Re: Very lumpy idle
Post by: krisbutler02 on March 16, 2013, 09:08:20 am
Here is a log from today with a bit more info

(https://www.mk5golfgti.co.uk/forum/proxy.php?request=http%3A%2F%2Fdaz.co%2Fmedia%2Fn19%2Fkrisbutler02%2FMk5saturday16thmrch.png&hash=020f0ace2d242f6a38eb24f197657a2be8f8b32b)
Title: Re: Very lumpy idle
Post by: krisbutler02 on March 18, 2013, 08:04:02 pm
The boost seems to be requesting low values and also fluctuating along with the maf reading fluctuating.

What could cause all these problems.

I need to take it to someone with the know how as im stumped.


This is stage 3 with all the mods you can get bar WMI so surely should be making alot more power than the calculated 307 bhp!