Lumpy derv

Ched · 7th April 2019, 18:11

I have a 75 diesel and on start up usually when cold but happens sometimes when warm, it is only firing on what appear to be 3 cylinders, a bit like a misfire,fires on all 4 after about 30/45 seconds, also get a bit of blue smoke till it runs properly.
Any ideas on what could be at fault here please?

bl52krz · 7th April 2019, 18:49

I would think it points towards a faulty Injector. Do a leak off test on them.

Ched · 7th April 2019, 19:34

Quote:

Originally Posted by bl52krz

I would think it points towards a faulty Injector. Do a leak off test on them.

Thanks, I was thinking the same but thought I'd ask on here as I'm a newbie to derv's.

LotusLC · 7th April 2019, 22:07

My car was exactly the same on start up, very lumpy. Then I started using Shell v power or BP ultimate and the car is perfect now. Maybe worth a try .

BigRuss · 8th April 2019, 11:16

It could be an injector but also check the injector wiring they have been known to break down with age

When it's "misfiring" try gently waggling the wiring to each injector in turn, if it disappears then that could well be the problem.

Russ

Ched · 8th April 2019, 12:33

Thanks Russ, I’ll try that, I’m also going to change all the filters, should be interesting 😉

7th April 2019, 18:11	#1
Ched I really should get out more....... MG ZT V8, MGZT 135 derv ,MG TF 135 Join Date: Dec 2011 Location: Romsey Posts: 2,293 Thanks: 553 Thanked 573 Times in 385 Posts	Lumpy derv I have a 75 diesel and on start up usually when cold but happens sometimes when warm, it is only firing on what appear to be 3 cylinders, a bit like a misfire,fires on all 4 after about 30/45 seconds, also get a bit of blue smoke till it runs properly. Any ideas on what could be at fault here please?

7th April 2019, 18:49	#2
bl52krz This is my second home Rover 75 cdt club + Rover 2.5 KV6 Conni SE Join Date: May 2008 Location: Birmingham Posts: 11,393 Thanks: 6,587 Thanked 2,262 Times in 1,729 Posts	I would think it points towards a faulty Injector. Do a leak off test on them. __________________ Great Barr, Birmingham.

7th April 2019, 22:07	#4
LotusLC This is my second home MG ZT CDTi Auto / ZT-T Trophy Blue Join Date: Nov 2013 Location: York Posts: 3,981 Thanks: 3,329 Thanked 1,644 Times in 1,238 Posts	My car was exactly the same on start up, very lumpy. Then I started using Shell v power or BP ultimate and the car is perfect now. Maybe worth a try . __________________ Lotus Carlton - Number 852 (My old car) https://i.imgur.com/Cwa3376m.jpg

8th April 2019, 11:16	#5
BigRuss Premium Trader 75 CDT Tourer,2.5 Launch Saloon, Omipro MG/Rover (T4) Join Date: Jul 2007 Location: Liversedge, West Yorkshire Posts: 5,405 Thanks: 1,105 Thanked 1,340 Times in 661 Posts	It could be an injector but also check the injector wiring they have been known to break down with age When it's "misfiring" try gently waggling the wiring to each injector in turn, if it disappears then that could well be the problem. Russ __________________ Replacement Key Service http://https://the75andztclub.co.uk/...d.php?t=244732 Full T4 Testbook diagnostics available. Diesel ECU repair and replacement. Options enabled or disabled as required. Diesel X-Power 135 and 160bhp, Rover 1.8T 150 to 160 MG 160 V6 to 177 upgrades available P.M. for details.

8th April 2019, 12:33	#6
Ched I really should get out more....... MG ZT V8, MGZT 135 derv ,MG TF 135 Join Date: Dec 2011 Location: Romsey Posts: 2,293 Thanks: 553 Thanked 573 Times in 385 Posts	Thanks Russ, I’ll try that, I’m also going to change all the filters, should be interesting 😉