1.8t misfire

Sheraton · 12th February 2018, 21:33

How'do folks

I had a nice wee drive tonight

...........then.....developed a problem

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

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

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

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 ?

i'll go back out for a look

later when she cools a bit - check the plugs at least

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

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 · 12th February 2018, 23:32

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

too cold to bother checking the rest.

plug 4 - i cleaned the plug and regapped to 0.60 - I'm not sure how

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

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

i cleared the engine codes, started her up.......and she idled Great

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

she ran great after that - pulling like a train

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

Paul.

T-Cut · 13th February 2018, 10:32

Quote:

Originally Posted by Sheraton

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 · 13th February 2018, 15:15

the plot thickens

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

fits with the issue i had -

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

So what actually happened

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

Can a T4 session identify faulty injectors ?

Paul.

Sheraton · 17th February 2018, 16:49

Update

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

still perplexed as to what caused this

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

seemed like a Good idea

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

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

but I'd like to know the cause

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

LoVe these cars

Paul.

Comfortably Numb · 17th February 2018, 19:57

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 · 17th February 2018, 20:16

i would try 4 new plugs 1st

Sheraton · 17th February 2018, 20:25

Quote:

Originally Posted by 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.

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

Paul.

LeRich · 18th February 2018, 18:40

Quote:

Originally Posted by Sheraton

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 · 20th February 2018, 14:55

UPDATE

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

I pulled up and plugged in my OBD scanner - RANDOM MULTIPLE MISFIRES

I cleared the code - drove the car no issues - then it happened again - this time misfire cylinder 4

I don't know..

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

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(?)

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

the Engine is not showing any other signs of an issue - and the misfiring clears almost as sudden as it appears

at least i will Gain some more Experience

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

any ideas ?

Paul.

12th February 2018, 21:33	#1
Sheraton Posted a thing or two Rover 75 1.8t Join Date: Oct 2015 Location: Edinburgh Posts: 1,377 Thanks: 384 Thanked 409 Times in 267 Posts	1.8t misfire How'do folks I had a nice wee drive tonight ...........then.....developed a problem 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 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 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 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 ? i'll go back out for a look later when she cools a bit - check the plugs at least p.s - i think whatever is the issue - it happened under load, i.e High Boost 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. Last edited by Sheraton; 12th February 2018 at 21:49..

17th February 2018, 20:16	#7
gary t Loves to post rover 75 connoisseur se v6 Join Date: Mar 2013 Location: brockworth Posts: 278 Thanks: 46 Thanked 23 Times in 20 Posts	Plugs i would try 4 new plugs 1st

12th February 2018, 23:32	#2
Sheraton Posted a thing or two Rover 75 1.8t Join Date: Oct 2015 Location: Edinburgh Posts: 1,377 Thanks: 384 Thanked 409 Times in 267 Posts	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 too cold to bother checking the rest. plug 4 - i cleaned the plug and regapped to 0.60 - I'm not sure how 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 I don't have any reason to think there's been any contact with the cyclinder i cleared the engine codes, started her up.......and she idled Great 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 she ran great after that - pulling like a train I'll have a better chance to see what's happening tomorrow - check the other plugs and the lower engine mount too Paul.

13th February 2018, 15:15	#4
Sheraton Posted a thing or two Rover 75 1.8t Join Date: Oct 2015 Location: Edinburgh Posts: 1,377 Thanks: 384 Thanked 409 Times in 267 Posts	the plot thickens 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 fits with the issue i had - 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 So what actually happened I'll go for new plugs and some Redex in the fuel.... Can a T4 session identify faulty injectors ? Paul.

17th February 2018, 16:49	#5
Sheraton Posted a thing or two Rover 75 1.8t Join Date: Oct 2015 Location: Edinburgh Posts: 1,377 Thanks: 384 Thanked 409 Times in 267 Posts	Update I've not done much mileage, however i have no issues with Misfires or Hunting Idle still perplexed as to what caused this 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 seemed like a Good idea I never gave it a thought initially - but it seems strange to be just coincidence 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 but I'd like to know the cause 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 LoVe these cars Paul.

17th February 2018, 19:57	#6
Comfortably Numb Posted a thing or two Rover 75 Saloon Join Date: Dec 2017 Location: Penrith Posts: 1,336 Thanks: 165 Thanked 303 Times in 241 Posts	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.

20th February 2018, 14:55	#10
Sheraton Posted a thing or two Rover 75 1.8t Join Date: Oct 2015 Location: Edinburgh Posts: 1,377 Thanks: 384 Thanked 409 Times in 267 Posts	UPDATE 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 I pulled up and plugged in my OBD scanner - RANDOM MULTIPLE MISFIRES I cleared the code - drove the car no issues - then it happened again - this time misfire cylinder 4 I don't know.. I'm waiting for her to cool - then i'll go out for a look at the plugs 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(?) I'm Hoping ALL my Plug gaps are still 0.60mm - if not the Engine is not showing any other signs of an issue - and the misfiring clears almost as sudden as it appears at least i will Gain some more Experience I have old Coils that were working fine - I'll try swapping these over....see wha'gwan any ideas ? Paul.