Cylinder 1-3 not working

LittleZ4

Active member
Afternoon all, I have a slight issue with bank 1 not firing. Background: I think I might have had a bad batch of fuel (unconfirmed).......the car started to run badly and jittery. It has now proceeded to only fire on cylinders 4-5-6 (bank 2). Prior to discovering it was bank 1 not working I changed the spark plugs for NGK ones as I had a brand new set waiting to go in.

The car will start but only runs on the rear bank. I had disconnected coil packs 1-2-3 and nothing changed. The coil packs are not particularly old either.

Not a lot of fuel had been put in but it did get run low. I can't believe that it's an injector issue as just the front bank failing on a common rail seems a little hard to believe.

Fresh fuel has been added.

Is the front bank controlled by a separate controller or have a separate fuse? I'm at a bit of a lose now........any help would be greatly appreciated
 
AFAIK the only "separate systems" between front and back are lambda sensors and cats. Everything else is homogenous.
 
The funny thing is that a dodgy lambda sensor would just throw errors. I wonder if the cat is catastrophically blocked?

Otherwise I suppose it's worth swapping coil packs front to back - the odds of 1-3 going bad together are 10 to the power of my overdraft but it's something.

Don't suppose you have INPA or a generic code reader?
 
smorris_12 said:
The funny thing is that a dodgy lambda sensor would just throw errors. I wonder if the cat is catastrophically blocked?

Otherwise I suppose it's worth swapping coil packs front to back - the odds of 1-3 going bad together are 10 to the power of my overdraft but it's something.

Don't suppose you have INPA or a generic code reader?

my thoughts exactly about the cylinders. Also tempted to go get some catless headers, there's some locally.

I have Carly but it threw up a load of codes that I just got disheartened and went in for a brew lol.

I haven't swapped the coils yet, that's a tomorrow job, also to top it off, the roof stopped working. Might just fix it with fire!!
 
So swapping the coils didn't change anything, still cylinders 1-3 not working. Potential blocked cat?? Catless headers may happen this coming week, she's already asbo enough without additional noise! :roll:
 
Although I did suggest it, the only trouble with the potential of a blocked cat is that it would have to be effectively completely capped off. A small thru-flow and, while it might not rev, it'd certainly idle.

I've just had a nose thru the wiring diagrams and the only other split circuit is the knock sensors. There's 1 per bank but they're in the same physical unit. Otherwise all the injectors, coils, etc are bunched together as a set of 6.

What was the lead up to this? Did it start running badly?
 
Plugs have been out many times to let the fuel evaporate from where it won't start.
I haven't tried or changed the injectors as it's definitely getting fuel, I could see a small amount on top of the piston
 
LittleZ4 said:
Plugs have been out many times to let the fuel evaporate from where it won't start.
I haven't tried or changed the injectors as it's definitely getting fuel, I could see a small amount on top of the piston

Have you tried cranking it over with the plugs out and connected/earthed to see if they spark?
 
Random thought. Am I right in thinking the front three coils have one earth lead and the rear three have another? I'm leaning on my M54 knowledge here.
On the grounds it is something common to those three cylinders, worth checking the strap is intact?
 
Hi LittleZ4,

What Chippie and EnuffZed said will at least get you "in the ballpark". For info, I can confirm there are two grounding valve cover studs on my N52 also - but your problem could alternately be a common power issue, so Chippie's approach makes sense too. Check the spark and the grounds.

Hope you find it and it's simple to fix !
 
enuff_zed said:
Random thought. Am I right in thinking the front three coils have one earth lead and the rear three have another? I'm leaning on my M54 knowledge here.
On the grounds it is something common to those three cylinders, worth checking the strap is intact?
I have taken the earth off and cleaned it up just as a precaution. It was in pretty good nick, all the wires seemed intact
 
LittleZ4 said:
Rockhopper said:
Are you able to do a compression test?
I don't have the equipment unfortunately. Can probably borrow it from someone. :D

I doubt you will have compression issues on all 3 cylinders to cause them to fail at the same time.
 
Chippie said:
LittleZ4 said:
Rockhopper said:
Are you able to do a compression test?
I don't have the equipment unfortunately. Can probably borrow it from someone. :D

I doubt you will have compression issues on all 3 cylinders to cause them to fail at the same time.
Willing to try anything at the moment. I think it's unlikely that all 3 have gone at the same time, but at least it rules it out
 
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