1.8t misfire

[Sheraton]

How'do folks :)

I had a nice wee drive tonight :cool: ...........then.....developed a problem :duh:

Good news is - I made it to the junction about 20yds from my street before it happened ;)

I'd given her a bit of welly before slowing for a junction and she stalled when i came to a stop :shrug: didn't start first turn, but did second try.

I drove up and down my street a bit and she was running Good with a bit of throttle - when i sat to let the car cool the revs were hunting - when i left the car to idle it settled - then i turn off and on again - and it's hunting :shrug:

I tried resetting the IACV (?) pressing the throttle 5 times - better, but still hunting after a throttle blip and a bit rough - after a minute the check engine light illuminated :cool:


codes are p0304 cylinder 4 misfire

p0313 misfire due to low fuel - this code appears twice - i thought maybe historical codes from a couple of overboost issues i had that didn't illuminate the check engine light ? :shrug:


i'll go back out for a look :shrug: later when she cools a bit - check the plugs at least :D



p.s - i think whatever is the issue - it happened under load, i.e High Boost :D

lol....never asked my questions ;)

which is cylinder 4 on a K-series ?

is it likely to be anything other than Plug/lead or injector ?


Paul.

[Sheraton]

a Wee update ;)


I've been out and pulled plug 4 (last on the right hand side as you face the engine)(i'm sure it is) i pulled this plug anywho :D too cold to bother checking the rest.

plug 4 - i cleaned the plug and regapped to 0.60 - I'm not sure how :shrug: but the Gap was way low 0.30 - admitted the plug slipped from my magnet back into the socket, wouldn't think this would have reduced the gap tho :shrug:

I don't have any reason to think there's been any contact with the cyclinder :shrug:

i cleared the engine codes, started her up.......and she idled Great :D let her run for a minute.....no misfire, no check engine light - took her for a quick run and had a strange moment 100yds from home.

the car seemed to vibrate and seemed like it was engine related - and i thought she was going to stall out again - this cleared after about 10 seconds :shrug:

she ran great after that - pulling like a train :cool:


I'll have a better chance to see what's happening tomorrow - check the other plugs and the lower engine mount too :getmecoat:




Paul.

[T-Cut]

which is cylinder 4 on a K-series?
Just so you know, by convention for any car engine, No1 cylinder is that closest to the crankshaft pulley (defined as the 'front' of the engine). So, the all in-line configuration simply counts cylinders from front to back. Hence on the K18, No4 is furthest right as you look at it.

Engines configured as a V, W or a radial array of cylinders get more complicated as manufacturers tend to apply their own rules.

TC

[Sheraton]

:shrug: the plot thickens :D


Been out to check the car today - I done the obligatory Coolant/Oil level checks, all Good ;)

I checked the Car for error codes (no check engine light) i expected something after last nights test drive and the issue i had - 1 code stored - cylinder 3 misfire :cool: fits with the issue i had - :shrug: but why now cylinder 3

I cleared the code - pulled and checked the plugs, Gaps were all Good - I cleaned the plugs and refitted - started the car, No hunting at idle no apparent misfires :} I ran up and down the street a couple of times and she idled a bit - no issue, no check engine light and i checked for error codes - clear :D


So what actually happened :shrug:

I'll go for new plugs and some Redex in the fuel....


Can a T4 session identify faulty injectors ?



Paul.

[Sheraton]

Update ;)

I've not done much mileage, however i have no issues with Misfires or Hunting Idle :cool:

still perplexed as to what caused this :shrug: something happened that resulted in the reduced plug gap in cylinder 4 and caused the car to stall - the misfire was persistent in cylinder 4 enough to illuminate the check engine light.


Could this be the result of a Backfire ? or a Back Pressure issue ?

the reason i ask is earlier that day I drilled a small (drain) hole in my backbox :shrug: seemed like a Good idea :D

I never gave it a thought initially - but it seems strange to be just coincidence :shrug:

coupled with the fact - I accelerated HARD in 2nd gear (1.8 turbo so high boost pressure) then let off the throttle to brake for a junction - this is the moment the "Event" occurred - and the car stalled.

I put a self tapper in the exhaust to seal the hole anywho ;)


I'm Glad she's running fine - and cleaning/gapping the plugs has sorted the misfire and cleared the check engine light :cool: but I'd like to know the cause :shrug: I feel the whole misfire/plug gap was a Symptom of something else ?


I'll drive her more tonight and tomorrow - but she seems no worse for it :bowdown: LoVe these cars :cool:



Paul.

[Comfortably Numb]

If it is anything like the MGF, it has 2 coil packs, 1 for cyls 1&2, the other for 3&4, working on the 'wasted spark' principle. I wonder, as both faults were for 4, then 3, whether it is coil-related? Perhaps with giving it some welly, the coil is starting to fail at high temperatures/demand? A full T4 diagnostic would hopefully show up exactly where the problem is.

[gary t]

i would try 4 new plugs 1st :}

[Sheraton]

If it is anything like the MGF, it has 2 coil packs, 1 for cyls 1&2, the other for 3&4, working on the 'wasted spark' principle. I wonder, as both faults were for 4, then 3, whether it is coil-related? Perhaps with giving it some welly, the coil is starting to fail at high temperatures/demand? A full T4 diagnostic would hopefully show up exactly where the problem is.


I'm sure on the 1.8t 1 coil feeds 1 and 4 the other coil feeds 2 and 3. (Coil on plugs 1 and 3)


;) Car NEVER gets pushed over 2500rpm until it's been at ideal temp for a reasonable time - i use the OBD coolant temp display for EVERY journey - when that's been around 90 for a bit, I can assume the Oil is at a Good operating temp - and i always sit and let the car cool after a journey :D



Paul.

[LeRich]

I'm sure on the 1.8t 1 coil feeds 1 and 4 the other coil feeds 2 and 3. (Coil on plugs 1 and 3)
This is correct.

[Sheraton]

UPDATE :D


I never got to drive her til today - started fine and drove fine initially - then, on the same bit of Road (where i had the vibration misfire cylinder 3) (low revs) - the same Vibration, then check engine light, then light flashing - into neutral and coasted looking for where i'd stop, before i stopped it cleared and the check engine light went off :shrug:

I pulled up and plugged in my OBD scanner - RANDOM MULTIPLE MISFIRES :D I cleared the code - drove the car no issues - then it happened again - this time misfire cylinder 4 :shrug: I don't know..


I'm waiting for her to cool - then i'll go out for a look at the plugs :shrug:

obviously - Coils, Plugs/Leads, Injectors (?), Fuel Pump (?) Coolant temp sensor (?)(i'd expect the temp displayed to be way off if this had gone tho ? ) MAP sensor(?) :shrug:

I'm Hoping ALL my Plug gaps are still 0.60mm - if not :getmecoat:


the Engine is not showing any other signs of an issue - and the misfiring clears almost as sudden as it appears :D at least i will Gain some more Experience :cool:


I have old Coils that were working fine - I'll try swapping these over....see wha'gwan :}

any ideas ?


Paul.

[Mischief]

Mine had the exact same issue, I changed the coils, HT leads, new spark plugs gapped to 0.5mm and a new boost control solenoid zero issues since. I still have startup issues but I think that is down to the orange clip fix needing to be done as once it starts it runs perfect.

For the solenoid I used my car battery charger to test it, hooked the leads up to the relevant positive and negative poles and heard no click tested the new one in the same way and got the click.

I'm sure I didn't need to change everything listed above however I thought better safe than sorry.

[Sheraton]

:duh::duh::duh:

checked plugs :shrug: Gaps all Good

swapped out the coil packs/leads for old ones that worked fine before being removed.

the car started no problem - then pretty much instantly started knocking :duh: :shrug: made me think a piston was hitting a plug ?

Pulled the plugs - nothing obvious - Gaps where Good - I assume i'd see if it were hitting ?

swapped coil packs/leads back again - hmmmm.....doesn't want to start :shrug: will just start with throttle....but won't idle...and using throttle to keep her running - she is ROUGH and does NOT sound Healthy :shrug: I don't know

gave up for tonight :getmecoat:


I don't get it - Unless the knocking i heard was caused by misfires ? - is this likely ?

Could the timing belt have slipped ? - i don't get how she'd be running smooth at any point if timing was off tho ?

Dual Mass Flywheel ? ......or is my imagination taking over - I'm not to up to speed on this :shrug:


it is NOT a Good time financially - and I need my Car to carry tools to work to make the money to pay to fix the car so i can get to work to make money to fix the car so i can......lol...... :D i'm sure we all know that story ;)


I'll try and get Coil Packs/leads/plugs at the weekend - If i can get to work and make the pennies (i'll manage :cool: ) and if there is more Going on......well i'm not sure...... I have NOT a Good feeling about this time :o


Paul.

[Sheraton]

:} How'do folks

I've been having a wee think about this - I'm going to be BOLD :D and Say - I'm putting my Money on the TIMING BELT HAS SLIPPED resulting in ALL these Issues I Experienced :shrug: may be wrong but I'll Investigate when i Get an Opportunity ;)

It would Explain the Initial Stall I had and misfires since - right down to vibration - and KNOCKING :eek: Hopefully IF i am on the right path, it won't have done too much damage :o - .....if it is a slipped belt - at least i'll know what happened :D


I'm sure she'll be FINE with a new belt and tensioner :shrug:



I'll need to have a wee look at how you go about checking the timing - it's a "Special K" :cool: so it'll be a simple task i'm sure :D


Paul.

[Sheraton]

UPDATE

How'do folks :)

thought i should update this thread as i had started a specific "Possible Slipped Timing Belt" thread ;)


It WAS a Slipped Timing Belt - Caused by the Tensioner Losing tension on the belt.

for Now i've retimed the Engine and adjusted the Tensioner - the Car is Running and Driving :cool:

She is a wee bit lumpy at idle So there may be some damage - it's not major tho as she drives smooth as always ;)

I've a wee bit more investigation to do - compression test etc.. and, obviously i'll be looking for at least a new tensioner.... probably a new belt too :}






Paul.

[Sheraton]

How'do folks :)

thread update now that All issues are dealt with :cool:


more details here

https://the75andztclub.co.uk/forum/showthread.php?t=279736

and here ;)

https://the75andztclub.co.uk/forum/showthread.php?t=287791



Paul.