Misfire horror LOL *update*

[Shaunyboy]

Hi all ive now rebuild my engine and got it running, now its missfiring badly and is running on about 2 cylinders, i took #1 coil pack off and it was the same, took 2 off and it was the same, took 3 off and it was shaking its arse off, put it back on took 4 off and it was the same, so swaped them round 4 on 1 and 3 on 3 jubbled them up but marked ones that worked, and was the same, its poping and can smell the unburnt fuel in the cats. So im lost as to what it could be, there is a bit of oil went in the bore as it was assembled and the plugs keep coming out black, you think it could be time for new plugs as i got 2 old and 2 new in but they all spark aand so do the coils.

 

[Shaunyboy]

Anyone?

 

[LEE69]

If the coil packs are sparking ok, try a set of new plugs.

 

[Shaunyboy]

Right the mystery deepens i found out the cat was blocked and when it got warm it cut out streight away and stallled splutterd so removed that, and trust me it was baked, hammer n chisel for 2 days anyways it seems better now but still had that dreaded missfire so im halfway through taking the inlet off to have a gander in the ports and see what the valves are like check the gaskets.

Tonight i pluged each coil pack into the 1st plug and 3 of them just ticked now and again the arch inside the coil, and number 4 was a constant tick tick tick tick, so removed injector 1 & 2 plug and no change what so ever, so were only on 2 cylinders now 3 & 4, the number 1 plug is washed with fuel and number 2 is quite wet, 3 & 4 are coked up due to the excess oil in the cylinder from the rebuild which is burning off, clyinder 1 is still oily as its not burning, i know this wont cause the prboelm anyway.

So what do you guys recomend 4 coils and new plugs?

On my code reader it said cam position sensor, so whipped it off and noticed there was a few metal shaving on the sensor end and the wheel had a bit of oil on, cleaned it all up and that hasnt come back up.

 

[virdi]

Sorry to ask

...But when you say you rebuilt your engine.... what exactly did you do? and why? (as in what went wrong in the first place)

..also...are you qualified?

 

[adam cupra 20vt]

Right the mystery deepens i found out the cat was blocked and when it got warm it cut out streight away and stallled splutterd so removed that, and trust me it was baked, hammer n chisel for 2 days anyways it seems better now but still had that dreaded missfire so im halfway through taking the inlet off to have a gander in the ports and see what the valves are like check the gaskets.

Tonight i pluged each coil pack into the 1st plug and 3 of them just ticked now and again the arch inside the coil, and number 4 was a constant tick tick tick tick, so removed injector 1 & 2 plug and no change what so ever, so were only on 2 cylinders now 3 & 4, the number 1 plug is washed with fuel and number 2 is quite wet, 3 & 4 are coked up due to the excess oil in the cylinder from the rebuild which is burning off, clyinder 1 is still oily as its not burning, i know this wont cause the prboelm anyway.

So what do you guys recomend 4 coils and new plugs?

On my code reader it said cam position sensor, so whipped it off and noticed there was a few metal shaving on the sensor end and the wheel had a bit of oil on, cleaned it all up and that hasnt come back up.

Its not going to hurt to try new coilpacks and a set of plugs.....if there not knackered now sods law says they will be soon.

 

[Phillc]

Sorry to ask

..also...are you qualified?

 

[heatfan8]

Doesn't matter if he's not qualified........Its his car, he can do with it as he pleases. I have no qualifications and completely re-built my old mini van and am now studying to be an aircraft engineer!!

But 1 thing I would say is NEVER use a mix of spark plugs! for the sake of what....£20?? Get new ones! It is worth getting new coilpacks too, just so you can eliminate them if nothing else!

 

[MJ]

2 common mistakes can be made when rebuilding the 1.8 20vt engine and they are both associated with the vvt unit on the left of the engine (only fitted to some):

1. if you've had the cams out the vvt unit has been removed and the timing of the 2 cams using this unit has to be very precise, set up properly and requires a special tool to set it up.
2. if you use too much sealer on the rocker cover or under the vvt unit it will be sucked into the oil galleries and knock the timing out - which bring on the cam sensor fault.

 

[Shaunyboy]

Sorry to ask

...But when you say you rebuilt your engine.... what exactly did you do? and why? (as in what went wrong in the first place)

..also...are you qualified?

If you was arround long enough or botherd to even search for my threads on here you may know what went wrong,

Ive served 3 years in the motor trade and this is now coming upt o my 4th, i also have a level 2 imi award motor vehicle yes!

But not really crossed VAG's apart from the usual stuff so its a learning curve isnt it, all mechnaics have to ask for a second opionion as everyone has diffrent/varying knowledge dont they?

 

[Shaunyboy]

2 common mistakes can be made when rebuilding the 1.8 20vt engine and they are both associated with the vvt unit on the left of the engine (only fitted to some):

1. if you've had the cams out the vvt unit has been removed and the timing of the 2 cams using this unit has to be very precise, set up properly and requires a special tool to set it up.
2. if you use too much sealer on the rocker cover or under the vvt unit it will be sucked into the oil galleries and knock the timing out - which bring on the cam sensor fault.

Going to take the tensioner out and check it, also i noticed the timing is arround 1/4 - 1/2 roller out on inlet cam, when ive read up its normally about half out on the exhaust cam isnt it? this may explain my missfire. Also i got the tensioner kit for it, just a case of bringing the timing back and see what it s like then, if not il do a compression test and see what the cylinders are saying.

 

[ibizacupra]

If you was arround long enough or botherd to even search for my threads on here you may know what went wrong,

Ive served 3 years in the motor trade and this is now coming upt o my 4th, i also have a level 2 imi award motor vehicle yes!

But not really crossed VAG's apart from the usual stuff so its a learning curve isnt it, all mechnaics have to ask for a second opionion as everyone has diffrent/varying knowledge dont they?

although his question came across.. a bit.. you know.. ohhh.. I think he was just askign what had gone wrong to instigate the need for rebuild, and maybe that is a legacy of whats happening now?

just a thought.

I know I dont have time to research the background of peoples cars, when its them asking for help.. if you know what I mean



so you have spark, fuel.. but only 2 cylinders actually firing?
cat was blocked? as in melted? as in overheated and collapsed perhaps?

do you have access to vag-com for any codes thrown up?

when I see misfire cars I throw a set of known working coilpacks (4) and a set of plugs next if thats not fixed it... and work from there. you have probably already done this tho I guess.

 

[Shaunyboy]

Right its had 4 new bosch super4's in and ive jumbled the coils arround and its sitll the same, sooo its either the cam timing as said which is all being redone tomorrow, or the wiring on the coil harness burnt out so may need a repair loom, also going to do a leakdown to see if there is any bent valves i cant see there being as it idles and doesnt chudder and cut out streight away.

 

[heatfan8]

How much will a set of 4 coilpacks cost? Surely you're better off replacing them first to eliminate them, although it does sound like you have deeper problems.

 

[MJ]

You need to:

1.Scan for any fault codes - FIRST JOB!
2.Pull all the plugs out and connect them all up to check the sparks are present and correct
3.Whilst the plugs are out check the compressions
4.Check to make sure your getting fuel - just remove the pipe at the end of the fuel rail
5.Check the cam to crank timing - cam pully should line up with the mark on the cam cover, crank should be matched up with THE MARK ON THE FLYWHEEL TO THE MARK ON THE BLOCK.
6.The cam timing - the cams should face upward with the notchs at the top (facing straight up, any rotation on them will be a problem). With the cams lined up with the cam cover mark remove the cover and check that these marks are definatly at the top and have a 15 link gap (one may be slightly to the side of the mark) between the marks.

 

[Shaunyboy]

You need to:

1.Scan for any fault codes - FIRST JOB!
2.Pull all the plugs out and connect them all up to check the sparks are present and correct
3.Whilst the plugs are out check the compressions
4.Check to make sure your getting fuel - just remove the pipe at the end of the fuel rail
5.Check the cam to crank timing - cam pully should line up with the mark on the cam cover, crank should be matched up with THE MARK ON THE FLYWHEEL TO THE MARK ON THE BLOCK.
6.The cam timing - the cams should face upward with the notchs at the top (facing straight up, any rotation on them will be a problem). With the cams lined up with the cam cover mark remove the cover and check that these marks are definatly at the top and have a 15 link gap (one may be slightly to the side of the mark) between the marks.

Fault codes i am getting cylinder 1 & 2 missfire, random multiple cylinder missfire, i had cam position sensor curcuit malfunction but cleaned it up and it hasnt come back, and HS02 bank 1 sensor 2 which is dowwn to decat.

spark is intermittent on most cylinders, and depends what it wants to do but all coils have sparked, which may lead me to belive ive sufferd a burnt loom as quite a few are cracked, just the casing the wire hasnt compleatly broke.

plenty of fuel plugs are wet and have let the pump kick in with return hose off and there enough pressure/fuel coming through, inlet gasket there is 2 and a smear of jointing compound on them. all studs/bolts tight and correct,

Crank to cam is spot on, checked that allready, cam timing is 16 rollers and one is half out which i read is ok on the exhaust, but mine is on the inlet even though it was right at time of install.

I will take the tensioner off tomorrow as it may be bloced due to sealant, no harm double checking, and i will borrow a compression tester tomorrow once im happy timing is correct, and am going to take the insulkation off the loom and see whats what, ive had it with a merc 320E which i serviced and it misfired like mine is and that was diagnosed at a burnt loom, and took me best part of a day to remove one loom of a scrapper, and install it, but i know of repair kits from euro.

 

[MJ]

Very rare for a loom to burn out on a leon to be honest mate. i'm not saying to overlook it, its just not very common.

 

[LEE69]

Someone did have a loom problem to the injectors.

 

[Shaunyboy]

See ive just moved the loom over to the battery side while the heads been off so its been moved about a few times and same as the injectors thats been moved across, Il check timing then it looks like coil packs.

Also i know the wiring isnt common but it still happens it would definatly misfire if it was as bad as this