Misfire cylinder 2 1.8t - Page 2

Ste.Sales · 3rd August 2015, 21:34

Plug gaps are 1mm, using denso iridium. I swapped it with an ngk standard plug... Same result. I have read about reducing the gap tp .7mm but it has been running fine at 1mm (until misfire started) and it runs fine when the engine is warm.
Thankyou all for your input, its is greatly appreciated.

HenryD · 4th August 2015, 08:21

Quote:

Originally Posted by Ste.Sales

Past 2 weeks i have had a misfire for around 5 mins when the car is first started from cold. Obd2 confirms cylinder2 misfire. Once warm it runs perfect. It also runs perfect if started again a few hours after previous drive. However the misfire returns if left for a long time, ie overnight.
I have swapped plugs over, swapped coil packs, swapped ht leads and injectors..still misfire cylinder 2. Compression tested cylinders:
No1 -160
No2 - 175
No3 - 180
No4 - 175
I have no coolant loss. There is no oil in coolant and no coolant in oil. Plenum is dry.
Any ideas? Thanks

Misfire could be caused by an injector playing about,try swapping out that one with another and see if fault goes with it,you seem to have covered the HT side of things.

beinet1 · 4th August 2015, 08:43

It could also be caused by low fuel pressure (partly separated fuel filter huousing (FFS)???), burnt/sticking valves, bad injector, O2 sensor bad...

HenryD · 4th August 2015, 10:29

Quote:

Originally Posted by beinet1

It could also be caused by low fuel pressure (partly separated fuel filter huousing (FFS)???), burnt/sticking valves, bad injector, O2 sensor bad...

02 sensor shouldn't matter from cold when running open loop

Ste.Sales · 4th August 2015, 11:31

Im starting to think its going to be a mechanical issue... Sticking valves perhaps. I swapped cylinder 2 injector with no4. No difference. I also checked resistance of the injector coils, all good. Checked wiring loom for injectors too. No breaks and obvious sign of damage. Would low fuel pressure cause only one cylinder to misfire? (And the same one at that). Well i only have a few days before my holiday, then i will strip the engine down and have a look.
Ps. I nnoticed today that the engine is making a fair bit of hydraulic lifter noise (heavy tapping) for a minute or so after startup... It didnt make this noise on saturday (3 days ago), coincidence?

Saga Lout · 4th August 2015, 17:16

It could be condensation in the plug hole that's shorting out to the head, then it warms up and evaporates. I'd try shining a torch in number 2 plug hole before trying to start it to look for moisture.

Ste.Sales · 15th August 2015, 18:09

Hi fellow members. Its been nearly two weeks since my last post. I have finally solved the misfire mystery. First of all, i would like to thank everyone who gave input and helpfull advice.... Thanks

Right... I have had a bit of a nightmare thats ended up costing me a few hundred quid. To cut a long story short, one of the exhaust valve springs was broken! It was still holding the valve in but not sealing it, maybe a half mm from the valve seat. Also the cam follower for this valve was shot too. The nipple in the center was almost flat! Another problem i encountered were the camshafts, both had very heavy scoring on the bearings. So, i bought a new cylinder head with valves, new camshafts, new followers, new cam belt + tensioner + water pump plus oil and filters and other miscellaneous bits. Spent a day rebuilding it and now runs sweet as a nut. Wife is now happy! So am I, used her credit card haha. Would post some pics but i have no idea how.

T-Cut · 15th August 2015, 21:20

Quote:

Originally Posted by Ste.Sales

I would post some pics but I have no idea how.

Excuses not allowed: http://www.the75andztclub.co.uk/foru...d.php?t=222759

In Point 10, the image should appear within your message GUI before you send/save it. That way you can check it's the right one and of the correct size.

Photos taken directly from a camera/phone may be ultra large (eg 2500-3000 pixels wide) and are best resized to around 800 pixels before uploading to Photobucket. That way you don't post any images that take up the whole screen or maybe two screen widths of the browser. The forum software might resize some oversize photos, but many seem to get through and make a mess of the layout (IMO of course).

TC

Ste.Sales · 15th August 2015, 22:43

Thanks T cut, will get on it in the morning.

4th August 2015, 17:16	#16
Saga Lout This is my second home MG ZT and Rover 75, Join Date: Jul 2013 Location: Wigan Posts: 3,276 Thanks: 2,556 Thanked 2,685 Times in 1,037 Posts	Or It could be condensation in the plug hole that's shorting out to the head, then it warms up and evaporates. I'd try shining a torch in number 2 plug hole before trying to start it to look for moisture.

3rd August 2015, 21:34	#11
Ste.Sales Avid contributor Rover 75 Saloon Join Date: Jan 2015 Location: Preston Posts: 233 Thanks: 9 Thanked 37 Times in 35 Posts	Plug gaps are 1mm, using denso iridium. I swapped it with an ngk standard plug... Same result. I have read about reducing the gap tp .7mm but it has been running fine at 1mm (until misfire started) and it runs fine when the engine is warm. Thankyou all for your input, its is greatly appreciated.

4th August 2015, 08:43	#13
beinet1 Posted a thing or two Rover 75 2.0 V6 Auto Join Date: May 2011 Location: Sandnes - Norway Posts: 1,560 Thanks: 64 Thanked 283 Times in 174 Posts	It could also be caused by low fuel pressure (partly separated fuel filter huousing (FFS)???), burnt/sticking valves, bad injector, O2 sensor bad...

4th August 2015, 11:31	#15
Ste.Sales Avid contributor Rover 75 Saloon Join Date: Jan 2015 Location: Preston Posts: 233 Thanks: 9 Thanked 37 Times in 35 Posts	Im starting to think its going to be a mechanical issue... Sticking valves perhaps. I swapped cylinder 2 injector with no4. No difference. I also checked resistance of the injector coils, all good. Checked wiring loom for injectors too. No breaks and obvious sign of damage. Would low fuel pressure cause only one cylinder to misfire? (And the same one at that). Well i only have a few days before my holiday, then i will strip the engine down and have a look. Ps. I nnoticed today that the engine is making a fair bit of hydraulic lifter noise (heavy tapping) for a minute or so after startup... It didnt make this noise on saturday (3 days ago), coincidence?

15th August 2015, 18:09	#17
Ste.Sales Avid contributor Rover 75 Saloon Join Date: Jan 2015 Location: Preston Posts: 233 Thanks: 9 Thanked 37 Times in 35 Posts	Hi fellow members. Its been nearly two weeks since my last post. I have finally solved the misfire mystery. First of all, i would like to thank everyone who gave input and helpfull advice.... Thanks Right... I have had a bit of a nightmare thats ended up costing me a few hundred quid. To cut a long story short, one of the exhaust valve springs was broken! It was still holding the valve in but not sealing it, maybe a half mm from the valve seat. Also the cam follower for this valve was shot too. The nipple in the center was almost flat! Another problem i encountered were the camshafts, both had very heavy scoring on the bearings. So, i bought a new cylinder head with valves, new camshafts, new followers, new cam belt + tensioner + water pump plus oil and filters and other miscellaneous bits. Spent a day rebuilding it and now runs sweet as a nut. Wife is now happy! So am I, used her credit card haha. Would post some pics but i have no idea how.

15th August 2015, 22:43	#19
Ste.Sales Avid contributor Rover 75 Saloon Join Date: Jan 2015 Location: Preston Posts: 233 Thanks: 9 Thanked 37 Times in 35 Posts	Thanks T cut, will get on it in the morning.