Strange situation v6

thomas 75 connie · 31st March 2013, 11:04

Our v6 is running rough and using alot of petrol. We have changed the spark plugs and checked the coils and they are sparking. With coil removed engine still starts and runs as before ie lumpy and power loss.

mantianak · 31st March 2013, 11:23

Have you done an error code scan? Might point to a sensor or misfire.

thomas 75 connie · 31st March 2013, 11:25

Quote:

Originally Posted by mantianak

Have you done an error code scan? Might point to a sensor or misfire.

We havnt a code reader I'm afraid.

SD1too · 31st March 2013, 11:38

Quote:

Originally Posted by thomas 75 connie

With coil removed engine still starts and runs as before ie lumpy and power loss.

Thomas,

I need to make sure that I understand this. You're saying that you've observed a spark from all six coils, yet the engine runs roughly. You then identified which cylinder isn't firing by removing one ignition lead at a time until you found one which, when removed, did not result in an increase in lumpiness.

Have I got that right?

Simon

thomas 75 connie · 31st March 2013, 11:41

Quote:

Originally Posted by SD1too

Thomas,

I need to make sure that I understand this. You're saying that you've observed a spark from all six coils, yet the engine runs roughly. You then identified which cylinder isn't firing by removing one ignition lead at a time until you found one which, when removed, did not result in an increase in lumpiness.

Have I got that right?

Simon

Sorry I havnt made myself clear.Yes you are correct in that fact they all spark but when each one is pulled out it still runs just as rough. Hope I've explained it better.

SD1too · 31st March 2013, 12:10

So that tells us that the rough running isn't being caused by the lack of a spark. So your plugs and coil packs are fine.

In your previous thread on this rough running I recommended that you carry out a full visual check of the inlet system looking for a leak of vacuum. That would be my next move, starting with the crankcase breather hoses which do become brittle and susceptible to breakage.

Simon

MangoMan · 31st March 2013, 12:28

I would also carry out a Compression Test.

mantianak · 31st March 2013, 13:03

Check the HT leads to see if the metal contacts on the inside are clean. If damaged they will appear black.

thomas 75 connie · 31st March 2013, 13:06

Thanks for all your input guys. Disconnected the lambda sensor and vis motors but still no different. We will look at the breather pipes/vacuum pipes aswell thanks

chris75 · 31st March 2013, 13:28

Borrow a fault code reader if you can . It might save a lot of fruitless tinkering

31st March 2013, 11:04	#1
thomas 75 connie This is my second home Rover 75 launch car x2, Rover 800 Vitesse Join Date: Jan 2009 Location: Plymouth Devon Posts: 8,463 Thanks: 1,115 Thanked 1,083 Times in 653 Posts	Strange situation v6 Our v6 is running rough and using alot of petrol. We have changed the spark plugs and checked the coils and they are sparking. With coil removed engine still starts and runs as before ie lumpy and power loss.

31st March 2013, 11:23	#2
mantianak I really should get out more....... ZT 190+ Saloon Join Date: Nov 2006 Location: Poole Posts: 2,413 Thanks: 6 Thanked 22 Times in 21 Posts	Have you done an error code scan? Might point to a sensor or misfire. __________________ http://i35.photobucket.com/albums/d1..._signature.png

31st March 2013, 12:10	#6
SD1too Doesn't do things by halves Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007 Location: Former Middlesex Posts: 20,592 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	So that tells us that the rough running isn't being caused by the lack of a spark. So your plugs and coil packs are fine. In your previous thread on this rough running I recommended that you carry out a full visual check of the inlet system looking for a leak of vacuum. That would be my next move, starting with the crankcase breather hoses which do become brittle and susceptible to breakage. Simon __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.

31st March 2013, 12:28	#7
MangoMan This is my second home Looking.... Join Date: Oct 2010 Location: England Posts: 10,911 Thanks: 862 Thanked 1,111 Times in 868 Posts	I would also carry out a Compression Test. __________________ *Regards, Bill - (MangoMan).* (Member 00854) http://i1110.photobucket.com/albums/...d.jpg~original

31st March 2013, 13:03	#8
mantianak I really should get out more....... ZT 190+ Saloon Join Date: Nov 2006 Location: Poole Posts: 2,413 Thanks: 6 Thanked 22 Times in 21 Posts	Check the HT leads to see if the metal contacts on the inside are clean. If damaged they will appear black. __________________ http://i35.photobucket.com/albums/d1..._signature.png

31st March 2013, 13:06	#9
thomas 75 connie This is my second home Rover 75 launch car x2, Rover 800 Vitesse Join Date: Jan 2009 Location: Plymouth Devon Posts: 8,463 Thanks: 1,115 Thanked 1,083 Times in 653 Posts	Thanks for all your input guys. Disconnected the lambda sensor and vis motors but still no different. We will look at the breather pipes/vacuum pipes aswell thanks

31st March 2013, 13:28	#10
chris75 same car since 2005 2001 Rover 75 2.0 v6 Connoisseur Saloon Join Date: Nov 2006 Location: Ellesmere Port , Cheshire Posts: 3,818 Thanks: 379 Thanked 549 Times in 466 Posts	Borrow a fault code reader if you can . It might save a lot of fruitless tinkering __________________ Who said it was simples ?