Entire bank 2 misfire

[Cowinthefog]

I have had this happen twice in the past month. It runs super rough right at start up. Shut down, restart, better. Third time, back to normal. No codes, only the Restricted performance notification which went away the third start. Then normal. Nothing to report.

Today, almost same exact sequence except for the random misfire code set along with misfire codes for 2, 4, 6 and 8 all at the same time with as near as I can tell, identical freeze frame data, which looked about as normal as I've ever seen it. MAF numbers looked same as when it ran fine, all fuel trims near zero, voltages near 14, fuel pressure good.

It's a daily driver and has been smooth, and gotten between 15-19 mpg.

The only thing I can think of might be the timing chains beginning to stretch. However, there have never been cam, crank or any other correlation codes and after the 3rd start each time it apparently self corrected. If bank 2 did slip a tooth, can the system correct for this, potentially twice? Meaning it slips, runs terribly, the system sees it, corrects itself and by the 3rd start it has self adjusted, and now having done it twice there is no wiggle-room left and I'd better better fix it? It still sounds good at idle right now so there seems to be no damage.

I've just resurrected my 2011 RRS with the same powertrain, so I'm relatively familiar with the system and will do the work, but haven't seen these symptoms yet.

Josh

 

[powershift]

I had a loose chain on mine when I bought it. No codes, just noise. Stick your finger in the oil fil and if you can move the chain then its too lose. I could move mine easily. Afterward its as stiff as a board.

 

[Cowinthefog]

Yes. I've had my eye on it. I just wondered if it could cause the symptoms I described. I have timimg parts coming...

 

[ugmw177]

i had an LR4 that was on original timing chains at about 100k. If you "goosed" right after start up like pulling out into traffic, it would sometimes give the restricted performance message and P0018 stored. I think the chain tensioners were close to their limit and before the oil pressure was built up it would show ECU a mismatch for cam timing. did not make noise and chain was not loose at least not then. no longer have that one so not sure if chains did need service later or what

 

[16FujiDisco]

Cam position sensor on that side going out? Or the cam solenoids?

Getting better with each restart sounds like the system is getting more/better data, then running as should be. I would think that chain stretch would be a more consistent issue

 

[powershift]

Yes. I've had my eye on it. I just wondered if it could cause the symptoms I described. I have timimg parts coming...

If the chain is loose then yeah, it could be related. I would expect cam timing related codes, miss-fires, limp mode, worse gas mileage.

 

[Cowinthefog]

Since I no other codes besides the 5 misfires and smooth by the 3rd start, I did check the chain through the oil fill cap. It was noticeably loose, so I went ahead and did the timing chains following the manual. It still did the same thing. By the 4th start symptoms were gone. Same codes. I'm starting to lean towards fuel injectors/sensors or pressure. I'll start checking tomorrow. I did do a quick check and noted that in drive at idle the fuel pressure (after the 3rd start) was around 250 at about 620 RPM. In park at the same RPM psi is about 435 and quickly rises with acceleration. Seems low.

But why all of one bank? Sensor? Injectors-how likely ally 4 fail at the same time? Or fuel ressure?

 

[scapistron]

Fuel rail comes up from the passenger side and feeds that bank and crosses over and feeds the driver's side. You might have a problem with the fuel pumps, my guess would be the in tank one. It is not priming the high pressure fuel pumps and those are struggling to suck fuel because they aren't designed to be self-priming.

JLR does have a pressure sensor on the low pressure side, but we can't read it with the GAP tool.

I don't know how to test the low pressure pump.

 

[Cowinthefog]

Started it twice this morning with no issue. I'll keep monitoring and post what I find. I have the iCarsoft 3.0. What data should I be looking for? The one thing it does not seem to see it low side fuel pressure, just the desired number.

 

[scapistron]

I don't think any obdii reader is going to be able to see it the way jlr setup these computers.

My one bad suggestion is to fill the tank and park on a steep decline. If it runs fine that way and like ***** parked in the opposite manner then I would blame the in tank pump. Problem is you'd have a full tank and dropping a full tank is the opposite of fun.