Misfire - not plugs or coil packs?!

Mine will be going this month hopefully Steve,
still not sure what to replace it with yet , was looking at a few new cars but do i want a car costing me £500 a month to run when i can do the same journey in a 2 year old car and cost me about £150 a month to run?
diesel or petrol , i have used your spreadsheet , cheers mate
with all the hastle i have had from SEAT , i just want to buy once this time and not get shafted again.
SEAT still not off the hook yet.

I cannot find something that matches the Seat, i haven't seen any of the issues people on here have, the only thing i have concerns about is water in the airbox, but trying to find something with similar performance less than 3 years old and under 12k is impossible. Oh my clutch is weak but that's my fault for remapping it.
 

Lee M

Guest
Did you do a cold and warm compression test?
My cold compression test showed everything normal , my warm test showed 3 cylinders with 1 bar of difference , so just doing the one test is not conclusive enough.

Rob

Hi rob. It was a cold test. I didn't want to be running the car with the fault.

I hope it is the injector as I'm right in the middle of a strip down, replacement and valve clean up! If not then ill be the master of inlet manifold removal :)

Did you have the same symptoms as me? Miss on idle only?
 

robdf2

Yellow is the best
Feb 21, 2006
3,605
3
location , location
Hi rob. It was a cold test. I didn't want to be running the car with the fault.

I hope it is the injector as I'm right in the middle of a strip down, replacement and valve clean up! If not then ill be the master of inlet manifold removal :)

Did you have the same symptoms as me? Miss on idle only?

missing on idle , but my spark plugs were lasting only 8k miles if i was lucky !

really bad fuel consumption and i mean really bad , my timing pull was all over the place on my standard car.
every independant i took it to said exactly the same but SEAT chose to ignore it because it wouldnt throw up a fault code.
and the reason why is beacuse no sensor was attached to the part which was at fault , go figure !
good luck with your injector change mate , take your time , post up if you need any help or guidance im sure we will be able to help you out.
 

Lee M

Guest
missing on idle , but my spark plugs were lasting only 8k miles if i was lucky !

really bad fuel consumption and i mean really bad , my timing pull was all over the place on my standard car.
every independant i took it to said exactly the same but SEAT chose to ignore it because it wouldnt throw up a fault code.
and the reason why is beacuse no sensor was attached to the part which was at fault , go figure !
good luck with your injector change mate , take your time , post up if you need any help or guidance im sure we will be able to help you out.

Cheers rob. Appreciate your advise. I have the special vag removal tool for the injector. I'm fingers crossed hoping that this is the fix.
My fault was apparent from cold though it didn't start after warming up. As soon as revs raise to 2k misfire stops.

Cheers
 

robdf2

Yellow is the best
Feb 21, 2006
3,605
3
location , location
Cheers rob. Appreciate your advise. I have the special vag removal tool for the injector. I'm fingers crossed hoping that this is the fix.
My fault was apparent from cold though it didn't start after warming up. As soon as revs raise to 2k misfire stops.

Cheers

no problem mate,

are you replacing all 4 injectors?
what are you using to clean your valves?
 

Lee M

Guest
no problem mate,

are you replacing all 4 injectors?
what are you using to clean your valves?

No mate just the one I think is faulty.

Finished thst task tonight. I've used carb/valve cleaner stuff from halfrauds, by Wynns. Works very well.
Then an old flat head screw driver that's a bit rounded off to loosen the stubborn lumps, tooth brushes, pipe cleaner brush, rags and a lot of fiddling about!

Turning the crank manually where needed to keep the valves closed to prevent crap falling into the bore.

At 29k!!:

Before
rupe4e7a.jpg


After
dezuvahe.jpg
 
Last edited by a moderator:

Tfsi_Mike

Active Member
Aug 30, 2007
2,386
6
Doncaster / Germany (Army)
Good effort on the DIY port valve clean dude.

I had a persistent missfire. Cyl 3. Swapping coils or plugs didnt move it to another cyl.

Tried the usual PCV, DV, MAF, new coils, plugs (My car gets new plugs at 5k usually anyhow)

Basic measuring was counting the misfire constantly at idle. Blipping the throttle or driving stopped the counting (but detection was disabled in basic measuring when on the throttle apparently) Could hear it burping and 'hicuuping?' on idle too. Wasnt notably not as smooth as normal.

Under load it was intermittent but got really bad at one point.

Got a basic compression test that showed healthy.

Long story short (bit late for that lol) New injector from Dave at SERE and it was good as new.
Perfect idle and no high load missfires.
 

Lee M

Guest
Good effort on the DIY port valve clean dude.

I had a persistent missfire. Cyl 3. Swapping coils or plugs didnt move it to another cyl.

Tried the usual PCV, DV, MAF, new coils, plugs (My car gets new plugs at 5k usually anyhow)

Basic measuring was counting the misfire constantly at idle. Blipping the throttle or driving stopped the counting (but detection was disabled in basic measuring when on the throttle apparently) Could hear it burping and 'hicuuping?' on idle too. Wasnt notably not as smooth as normal.

Under load it was intermittent but got really bad at one point.

Got a basic compression test that showed healthy.

Long story short (bit late for that lol) New injector from Dave at SERE and it was good as new.
Perfect idle and no high load missfires.

Better late than never Mike ;-)

You've described exactly what my car was doing.

Re- assembling on Saturday. Thought I'd make the most of access to the valves to get them clean.

Did you just swap out one injector?
 

robdf2

Yellow is the best
Feb 21, 2006
3,605
3
location , location
its funny actualy because if you speak to SEAT about the missfire counter on tickover they say this is normal and the lumpy missing is also normal on tickover , infact they stated this in one of the many letters they sent me regarding my car.
I had complained that i got over 40 missfire counts on idle in 30 seconds , there actual words were that this is not a missfire but a missburn caused by the aggressive nature of the camshaft.
Draw your own conclusions from that reply , it seems that owners know their cars alot better than the manufacturer !
 

robdf2

Yellow is the best
Feb 21, 2006
3,605
3
location , location
No mate just the one I think is faulty.

Finished thst task tonight. I've used carb/valve cleaner stuff from halfrauds, by Wynns. Works very well.
Then an old flat head screw driver that's a bit rounded off to loosen the stubborn lumps, tooth brushes, pipe cleaner brush, rags and a lot of fiddling about!

Turning the crank manually where needed to keep the valves closed to prevent crap falling into the bore.

At 29k!!:

Before
rupe4e7a.jpg


After
dezuvahe.jpg

Very nice indeed mate , well done :thumbup:
 

Tfsi_Mike

Active Member
Aug 30, 2007
2,386
6
Doncaster / Germany (Army)
Want to come and help clean my inlet Lee? :p

My way of thinking really wanted to change all 4 injectors at the same time but I ended up just doing the cyl3 due to cost. Immediately noticeable better idle when picked up from the dealer and not missed a beat since.


Rob some of the replies you got where really laughable, that is unreal.
 

robdf2

Yellow is the best
Feb 21, 2006
3,605
3
location , location
Want to come and help clean my inlet Lee? :p

My way of thinking really wanted to change all 4 injectors at the same time but I ended up just doing the cyl3 due to cost. Immediately noticeable better idle when picked up from the dealer and not missed a beat since.


Rob some of the replies you got where really laughable, that is unreal.

Your telling me Mike ,

Honestly thats exactly what they told me in writing.

And you remember when my door dropped and damaged my wing , they inspected the car and in writing told me that it was not a manufacturing fault or defect from factory , them i proved the bolt was missing from the door hinge , then they replied that actually it was a manufacturing defect , seriously you cant make this sh*t up
 

Lee M

Guest
If after moving the plugs around AND moving the coilpacks around. If the missfire still hasn't moved cylinders. If it is an injector problem its obviously the injector on that 1 cylinder.

Doesn't seem worth moving each injector around to see if the miss fire moves?

I agree mike especially as getting to and removing the injectors is a bit of a mission!
 
Jun 26, 2008
1,142
1
Just round the corner.
Good write up Lee,
Mine has similar symptoms, (although when Mike scanned mine, I only had 4 miss fires).
Will have to get mine looked at, as the miss fires are not isolated to one cylinder.
 

Lee M

Guest
Good write up Lee,
Mine has similar symptoms, (although when Mike scanned mine, I only had 4 miss fires).
Will have to get mine looked at, as the miss fires are not isolated to one cylinder.

Hi mark,
Mine still has similar symptoms to yours sporadically. I get very minor misses on random cylinders.
Seems very common place on these engines.
I changed all my coil packs. This has improved things so I now only get one or two every now and again.
 
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