Missfire under load - S3 engine

[F17BAD]

Hi folks

AMK lump, brand new red top TFSI coils, brand new NGK 7's gapped to 0.7

misfire intermittent when hard load shifting up from 2nd to 3rd and 3rd to 4th

ease off throttle and foot down again its fine

Tried another set of TFSI coils - same problem

Tried my old S£ coils (they were working fine) and the problem still here

tried old NGK platinum plugs (also were working fine) and the same problem happening, treid these plugs with all the coilpacks listed above


unplugged MAF, issue still their

The maf is a year old, genuine Bosch, anyone think this could be the issue ??

Engine has just had a boost leak test and i found 3 big ones, the missfire has happened since iv fixed these leaks


AMK engine with MTM turbo kit - RS2 Turbo

Injecors were cleaned ultrasonically 1000 miles ago. car only run on high octane fuel

MAF is my next purchase???

 

[<tuffty/>]

Done any logging or checked for any fault codes?

<tuffty/>

 

[jezzy]

check your loom to the coilpacks mate. they breakdown over time, undo all the tape of the loom to where it joins the main loom.
see if theres any holes or cracks in the loom wiring and fix.
costs about an hour of your time and a roll of insulating tape

 

[s3dave]

Sounds odd but see if you have any pedal switch faults logged, these can interfere with the ecu

 

[F17BAD]

Sounds odd but see if you have any pedal switch faults logged, these can interfere with the ecu

thier was a pedal switch fault but its now gone

i might add this engine is installed in a VW GOLF MK3 GTI

no codes on vagcom at all now tho,

did get random missfire and missfire on cylinder 2 and 4

cleared codes they have not come back yet its still the same

 

[s3dave]

Hesitation Problem - Page 3 - SEAT Cupra.net - SEAT Forum

 

[<tuffty/>]

Ok... may have helped to know the details of the install as its far from std lol... but... make sure the earths are good on the cam cover adn assuming you have wired the loom correctly that all the earths for the rest of the loom are correct... you could try a jump lead from the battery earth to the cam cover where the earth for the loom fixes to see if things improve...

I assume you are running ME7 ecu? not standalone? I also assume the mapping is the MTM map for the kit?

<tuffty/>

 

[F17BAD]

Hi mate

right a few more details onthe conversion

its been installed 2 years now on factory Audi ECU and all audi looms

i installed it myself it's total OEM super clean.
it has forged rods etc etc basically fully rebuilt her when we did the conversion. Engine has covered 41k in total it's a 2004 dated lump

mtm kit uses the RS2 hybrid turbo and that was rebuilt by grant Parker who is well know round my area, all other parts of the kit were bought new from kim Collins seals etc
it runs no cats and the Downpipe is modified to suit the Vw
kim got MTM in Germany to write a map for it and tbh it's a clean map but I'm having a custom one done, my tuner has broke their protection code and looked at the MTM map, it's very gay in regards to the timing etc. it only runs at 10psi too so the turbo hardly even has to work. The MTM base map is quoted at 330bhp

the injectors were fully cleaned 1000 miles ago

no other issues with the car, can only get it to do the problem when I very hard accelerate from 2nd to 3rd gear and the same from 3rd to 4th. If I ease off and put foot back down its fine. its only started doing it from my knowledge since I fixes 4 big boost leaks the other day


ill get some pics of the engine

 

[badger5]

i would be looking at your fueling if you are 100% confident its not ign based misfire.
lean misfire also something to consider.

log your fueling on 001 and 031 and see what you get

 

[F17BAD]

Bill
I have noticed more black deposit on the exhaust and on the spark plugs which are brand new (gapped to .7)
wiped them down did a 2 mile test run they were full
of black sut again.

i only have free version of vag here. Can i log on this ?

 

[badger5]

egt probe working ok?
you cant log the channels we would want to see on the free on I dont think.. only goes to 020 does'nt it as max channel?

001,002, 031: 001 will be fuel trim live lambda adaption adjust %, 002 airflow and injector ms, and 031 request vs actual lambda

112 is egt.... if in fault mode or if its running uber hot it will fuel dump.
any faultcodes re egt?

black soot is either its just cold starts and minimal running but if thats not the case its over fueling for some reason.. 031 should show the fuel request
you really do need to invest in vcds else you are running blind

 

[F17BAD]

I did get a code for EGT. Code 17861
where is this located bill ?

cheers

 

[F17BAD]

Actually thinking about it I removed this probe when I fitted the MTM kit as I had nowhere to install it ??

 

[s3dave]

^^oops^^

 

[F17BAD]

Their is no place for it to mount on the MTM kit

the probe was in my ko4 housing and that's no longer on the car. I do have it all in my garage tho.

 

[s3dave]

I think you will need to get a boss welded in so it can be fitted, im guessing you will be getting bad cylinder wash with that removed..

And the MTM Map as not coded it out as it is throwing up the code...

 

[F17BAD]

Trying to get a answer from kim at QST!!
​

 

[<tuffty/>]

I did get a code for EGT. Code 17861
where is this located bill ?

cheers

17861 - Exhaust Gas Temp Sensor 1 (G235); Open or Short to Plus
P1453 - 35-00 - -

There's your problem... no EGT probe and not coded out... it will be pouring all the fuel in mate... get it sorted pronto as it will be causing bore wash... I have personal experience of this and it ruined my piston rings in not a lot of miles...

StaceyS3 had a boss welded into the hotside on his for EGT so they must do it...

<tuffty/>

 

[F17BAD]

what size boss do I need and where do I need to install it ?

Its never done this missfire issue before tho so I don't know if its related or not.
ill scan the car again now​

 

[<tuffty/>]

If you are using ME7.5 ECU (the AMK one) with the correct S3 file then this is the issue mate... as said I have personal experience of this issue... the EGT probe normally goes into the hotside of the K04... Staceys was welded there too but I know his runs very hot... EGT's (for whatever reason) seem to be an issue here and AFR wasn't that great from what I remember on the MTM maps... its prob for the best its running rich lol

Bill sells bosses for EGT probes... we use these on BT builds and normally put them in the downpipe close to the turbo and map accordingly... I doubt you have much you can do there on yours as QST don't do the mapping...

<tuffty/>

 

[F17BAD]

I only put the MTM map on to get the car rurunning its going for mapping with my regular people who mapped my ko4
i don't like the MTM map, it's weak.
thing is why has it only started doing this issue since Iv fixed boost leaks ? It's been fine Before???

i think their was a blanked off hole in my RS2 housing come to think of it ( blanked off as tho It was done at manufacture stage )

hiw much are the bosses from bill ?

 

[F17BAD]

Got kim at QST on the phone now
MIT does need to be installed as he says I will have a boss on the housing !! I never saw one
he says big I get stuck he will get MTM to send a picture of the location

 

[<tuffty/>]

Air leaks, more air, masks the issue a bit I would imagine but trust me the fuelling is going to be rich as f00k... the map will go into a self preservation mode... under load/full boost it will missfire like mad... mine did this when I had the issue and was running into EGT protection as we had the EGT probe in the collector so was hitting the limit sooner..

Once I worked out where the maps were then its was easy to adjust the limit to suit position so if you are going for a custom map I would weld it into the DP as this is the easiest fitment... the mapping can be sorted from there... this is what I have done on mine... I have tweaked the mapping to suit the probes new position and tuned all the fuelling maps accordingly...

Give Bill a call for a price mate... its the best way to get hold of him...

<tuffty/>

 

[F17BAD]

Ill take the car off the road and look into what's on my housing then take it from their

 

[Prawn]

as soon as I read the thread title and username I knew it'd get confusing as it's installed in a mk3.

EGT is the issue here for sure mate as Bill and tufty have said, it'll also be making the car feel MUCH slower, having been out in a few S3's with, and then without EGT issues it really does kill the car.

 

[F17BAD]

Haha do u know the car matey ?

jesus the car Is really fast as it is !!!

its only been doing this issue a day since I fixed the boost leaks.

do you think any damage could have happened to anything ?

 

[<tuffty/>]

When I went to replace my non drilled rods for drilled ones I noticed the rings had worn very badly...

worn top comp ring

new top comp ring

I know the car and engine intimately and the rings were fine when I first fitted the non drilled rods and did the initial build... I have done a fair few rod changes and engine builds since and not seen wear like this..

I can only attribute this to when I was running with the probe in the collector and it was fuel dumping almost all the time (same as it does with it disconnected)...

They are not a cheap sensor to buy new (circa 170 quid with next to no discount) but the AMK/BAM maps fuelling strategies work off this sensor as std... its a useful thing to have but can be coded out easily enough

<tuffty/>

 

[F17BAD]

I still have my probe here and Iv just got off the phone to bill and ordered the bung to weld to my downpipe
he also told me the figures for the map etc so hopefully all is

only run the car for just over a day with the missfire issue so I hope I'm all good.
theirs no increase in my oil levels or anything like that either (fuel)

 

[F17BAD]

Just want to update this thread

well i got the EGT bung from Bill (cheers matey)

had it welded in to my Downpipe right the out let from the turbo housing ( very close to where the OEM location would be)

Whilst the downpipe was off, I also welded in a bung for a Air / Fuel ratio probe so i can fit one at a later date easily.

took the car out for a test drive and it not only feels even faster!!! but the missfire has now gone and its all normal. thers n hesitation when fast changing gears that i had before and theirs no black Sutt stuff on my exhaust pipes after every drive of the car

going to get the fuelling map changed as per what Bill told me whilst i was on the phone to him.

The car is off for a full custom map anyhow

Thanks to those who helped

 

[F17BAD]

Oh, and here is a few pics of the car / engine for those who are not familiar with it