2011 LR4 Misfire/rough idle

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

avslash

Full Access Member
Joined
Nov 22, 2011
Posts
1,255
Reaction score
1,101
Location
The Lone Star State
I got mine with 115k on the clock. My intakes are very nasty. Not sure all that crud would be good to go through the engine, so leaving it alone for now. I did turn my manifold on it’s end the last time I had it off, and it was crazy the amount of oil that drained.

I’ve considered a walnut blasting of intakes but have not done enough homework to weigh the pros/cons.


I have been considering this, as well, but it seems that only one or two places in Houston do it, and they are both BMW shops. I'm wondering if I would have to pull the manifold myself and trailer it over there.

I know @djkaosone did his at the time of his timing chain job, so maybe he will weigh in.

If you move forward, please let us know the results, how you accomplished it, etc.
 

mklinker

Full Access Member
Joined
Aug 3, 2018
Posts
115
Reaction score
31
Location
boston, ma
Have you tested the fuel pressure ? if you're having multiple/random misfires , fuel delivery might be you issue. I believe the fuel pressure should be btw 55 to 65 psi. O2 sensors just monitor the fuel ratio and will not cause a misfire. Several injectors cannot go bad at the same time so i wouldn't even check the injectors since the codes say multiple misfire. My best guess is your fuel pump or fuel filter.
the fuel pressure at the injectors is in the thousands. its a high pressure system.
 

Azoo

Full Access Member
Joined
Jun 23, 2017
Posts
116
Reaction score
22
Location
Brampton Ontario
the fuel pressure at the injectors is in the thousands. its a high pressure system.
Was talking about the pressure the pump gets out from the tank to the fuel rail, its an average of 55-65psi for most cars. Some cars have a valve/port on the fuel rail where u can test the fuel pressure with a fuel pressure tester.
 

djkaosone

'11 LR4 HSE LUX 5.0L V8
Joined
Oct 26, 2015
Posts
1,013
Reaction score
683
Location
SoCal
@scott schmerge and @avslash I did mine and it's worth it. After doing so, I placed an oil catch cans on each bank. To my surprise, bank 2 doesn't need it. Bank 1 on the other hand sucks a LOT of air from the intake manifold. The vacuum is ridiculous in bank 1.

I haven't measured it, but I've used 5/8" ID (Inner Diameter) black rubber HD fuel lines and the lines collapsed under vacuum. Then I used clear reinforced vinyl tubing with 5/8" straight through barb connectors just to see what happens. I drove about 20 miles with the heat and vacuum separating the inner hose with oil running through. In the meantime, I've put the stock pipe back on. I'm prepping up to build my own oil catch can out of aluminum that runs along the top RH side of the intake manifold. I've also ordered special 5/8" ID 11/16" OD PTFE tubing to handle the job. It has a higher tolerance to cold (-454* F) and heat (500* F).

Once I get the catch can done, I'll redo the walnut blasting.

First off get the proper tools, media blaster (gravity or siphon), fine walnut media, shop vac, extraction adapter, and blasting wand.

Siphon blaster: https://www.amazon.com/gp/product/B0007D30DO/ref=oh_aui_search_asin_title?ie=UTF8&psc=1

Walnut media: https://www.harborfreight.com/25-lbs-fine-grade-walnut-shell-blast-media-92155.html

Extraction adapter: https://www.ecstuning.com/b-genuine-mini-parts/extraction-adapter/81292208038/

Blasting wand: https://www.ecstuning.com/b-genuine-mini-parts/strahlsonde-mini/81292208032/

To do it right, remove the ignition coils, spark plugs, fan cowl, fan, throttle body (without removing any connecting tubes), and completely removing the intake manifold. Put the truck in Neutral, choke the wheels, and put on the ebrake. Put a dowel rod (I used a long skewer stick) into each spark plug hole to find the highest point of the piston to ensure the intake valves are completely sealed. Tape off ALL valves, except for the one you're working on. Then start walnut blasting it until it's clean and air blast it clean. Don't use any chemicals in there. I'm just not sure if it'll cause any damage, but I wouldn't use it. Rotate the engine crank clockwise till you find the next valve to work on.

The cheat way, remove the fan cowl, fan, throttle body from the intake manifold and completely remove the intake manifold. There should be only 1 or 2 valves visually open, don't blast it. Tape off ALL valves and blast each one until those are done. Rotate the crank clockwise until the remaining 2 valves are in the closed position.

I recommend doing it correctly, it's only an hour longer to pull those plugs and it'll give you a sense of accomplishment. I think the total time with beer breaks was about 3-4 hours. I spent about 5-10 minutes per valve and that right there is already 40-80 minutes for all 8 valves.
 

DonC

Full Access Member
Joined
Oct 3, 2018
Posts
99
Reaction score
62
Location
The Woodlands, TX, US
Well here is another one acting up with the exact same symptoms as what Dave was seeing. I replaced the 02's just a few weeks ago for normal scheduled maintenance and sure enough today on the way to work it started acting up. Spark checks fine but it is blowing gas out the tailpipe. Same error codes as what Dave reported so since he had good luck with the injector replacement it looks like i will be headed down this road as well. Dave if you have the write up please post it up. It would be a nice reference to have before I start this. Also where is everyone getting their injectors from? AB has a set that comes with a removal tool but not certain if that is needed or not.
Funny My 04 D2 is starting be the the reliable one in the family.
 

djkaosone

'11 LR4 HSE LUX 5.0L V8
Joined
Oct 26, 2015
Posts
1,013
Reaction score
683
Location
SoCal
Sorry for the late response... Check out my post on DIY Timing Chain, it pretty much gives you a sense of what's involved in the injector removal section. PM me if you have any questions or suggestions on where to get the parts.
 

DonC

Full Access Member
Joined
Oct 3, 2018
Posts
99
Reaction score
62
Location
The Woodlands, TX, US
Thanks for the help and the write up. I was able to source the Injectors off of fleabay for $680 and then the injector puller as well. Not bad in in with new plugs, PS valve cover (complete), injectors, tool, and a hitachi compressor rebuild kit for under $1000. Joe D. on this page is a land rover tech in Dallas and a fellow member of Texas Rovers gave me some pointers over the phone about how to make this even easier. One thing he recommended as adding a 6 inch bolt to the end of the injector puller. This gives you a little bit more force when using the slide hammer puller. 2 pulls and the injectors were out. All in all i would say an easier job than D2 headgaskets. I finished up late tonight so tomorrow will be my test drive. No codes so hopefully everything looks good from here on out.
 

Krill

Full Access Member
Joined
Oct 22, 2018
Posts
100
Reaction score
24
Location
Wellington Florida
So I read through this thread and agree I’ve got an injector issue but just want to see if y’all agree.

Few days ago tried to pass someone in traffic, car downshifted and felt rough upon acceleration. Immediately the “reduced performance” and check engine light came on. Limped home with a cloud of smoke behind the car(smelling of pure unburned fuel) next day checked coolant level and oil. Everything is the same as it’s been for months so not thinking it’s head gasket. Truck runs like it’s got a bad coil( installed 8 new coils and spark plugs) to no avail. Starting the car is getting harder( have to press the accelerator pedal in order for it to actually start up) do you agree the next logical step is injectors? It’s a 2011 LR4 v8 with 180k.

Throwing
cylinder 8 misfire 0308
Coil H circuit 0358
Coil A circuit 0351
Fuel rail pressure 0087
Misfire first 1000 rpm 0316
 

jpjp

Full Access Member
Joined
Sep 1, 2014
Posts
158
Reaction score
32
Location
Florida
I would say injectors based on my experience which sounds exactly like your experience.
 

scott schmerge

Full Access Member
Joined
Oct 9, 2018
Posts
612
Reaction score
284
Location
Charlotte, NC
@Azoo I would have thought the same thing in regards to the injectors. As a side note, I wasn’t sold on the o2 sensors causing the issue, but found that they needed to be swapped anyway due to mileage. I felt it best to spend money on regular maintenance items that needed replacement before throwing money at injectors just on the off chance it helped.

I just finished the injector install and the truck runs perfectly fine now. It’s been a long, arduous task trying to sort this out, but glad it’s back to working. There was a lot of ups and downs that I plan on detailing in a write-up. One thing I’ll recommend getting is a cheap code reader. That made a big difference when looking into sensors, vacuum, etc.

@TheDave, I’m about to embark on taking fuel rail off (I’ve got it broken down to there). Did you ever get around to doing a write up? Can’t seem to find one. @TheDave, @DonC, Any advice or lessons learned? I’m doing all eight injectors and plugs while in there. I have the passenger side broken down to fuel rails. Drivers side is about 1/2 way to rails.
 
Last edited:

Latest posts

Forum statistics

Threads
36,223
Posts
217,584
Members
30,473
Latest member
OnoA
Top