2011 LR4 Misfire/rough idle

[L Crist]

It doesn't sound like you have an IID Tool. Maybe you should get one to read the codes on your own. It's a big initial investment ($500), but it'll save you time and money from driving it around and allowing you to diagnose it yourself.

If you have one, I'd clear the learned adaptation values. You made a lot of changes where you want to force reset the adaptation values back to factory and allow it to dynamically adjust to your driving style.

This truck is VERY sensitive to vacuum leaks. Leaks will cause it to do weird things, like engine noise, loss of power, random misfires. With the engine running just spray soapy water all around the PCV, valve covers, hoses, and hose connectors on both sides to find any leaks.

I ordered one today! You're absolutely right. I DO need one.

 

[L Crist]

OK. Got my hands on a generic reader for now. On startup, i got:
P0003 Fuel Volume Regulator Control Circuit Low
P0301 Cyl 1 Misfire
C0700
P0303 Cyl 3 Misfire

 

[scott schmerge]

Not super familiar with high pressure fuel pump but sounds like you may have a short, a loose connection, corrosion, or faulty pump, etc... it sounds to be fuel delivery related by those codes, but gap tool may be able to tell you more. You can check specific pressures and values with gap tool. You won’t regret throwing down the 500 for it...

keep us posted. I’m sure someone on here more familiar can shed some light.

 

[L Crist]

OK, i'm back to a really rough idle when starting up cold. Codes galore. Yet it still runs great when warmed up! Oy vey.
1. P0003
Fuel Volume Regulator Control Circuit Low
2. P0301
Cylinder 1 Misfire Detected
3. C0700
Check report for description.
4. P0303
Cylinder 3 Misfire Detected
My LR guy now suspects it's sensor/ electrical related. I'm dropping it off at the garage this week and will report back if this solves it or not.

 

[djkaosone]

1. P0003
Fuel Volume Regulator Control Circuit Low

Sounds like your hpfp is on it's way out.

I have 2 used and perfectly working ones that I can part with, since, I prematurely threw money fixing a ghost problem. PM me.

 

[L Crist]

Hey guys! So I've since had the Low Fuel Pressure sensor replaced last week. I no longer get the code P0003
(Fuel Volume Regulator Control Circuit Low) but the engine STILL chugs, struggles and misfires on the odd number bank when cold. Literally as soon as the engine warms up (needle on temp hits exactly the middle) the engine runs perfect and restricted performance shuts off automatically. I'm getting the obvious cat code occasionally too as I know it's been through a ton of **** when the engine wasn't running well previously.

Why on earth is this only happening ONLY when cold? Something about the open/closed loop operation gone awry?

All that said, I've still been driving my truck daily. I adore this thing.

 

[L Crist]

OK, we have a fix! My indie LR guys finally threw their hands up and told me to take it into the dealership. The tech there tested EVERYTHING, fuel pumps etc and found that the coolant temp sensor was the issue. Boom, solved. By far, the cheapest fix too. Hope my issue and solution helps someone else out too!

 

[scott schmerge]

OK, we have a fix! My indie LR guys finally threw their hands up and told me to take it into the dealership. The tech there tested EVERYTHING, fuel pumps etc and found that the coolant temp sensor was the issue. Boom, solved. By far, the cheapest fix too. Hope my issue and solution helps someone else out too!

That’s awesome news. Good info


Sent from my iPhone using Tapatalk

 

[LarryK]

Hey Gang, new forum member here. I purchased an 11 LR4 a few weeks ago. Has 72K on it. Drove great for 2 weeks and that was it since I have had it. Have replaced the low and high pressure fuel pumps, all 8 injectors, and the crankshaft position sensor.
Still have a hard (long) start when cold and after some unspecified amount of time when running, I get a rough idle, check engine, and reduced performance warning. Definetly shows some improvement on power with the new parts but it only ran 60 or so miles before acting up again. Codes are showing misfires. After injector replacements, I did get a code for the Cat Converter one time but hasn't re-appeared. I'm several thousand dollars in and have the same result. The classic definition of insanity... Any thoughts from the group on this? Has anyone tried the Coolant Senor replacement and had the same effect as OP above? Any direction on next steps would be very helpful.

 

[djkaosone]

Hey Gang, new forum member here. I purchased an 11 LR4 a few weeks ago. Has 72K on it. Drove great for 2 weeks and that was it since I have had it. Have replaced the low and high pressure fuel pumps, all 8 injectors, and the crankshaft position sensor.
Still have a hard (long) start when cold and after some unspecified amount of time when running, I get a rough idle, check engine, and reduced performance warning. Definetly shows some improvement on power with the new parts but it only ran 60 or so miles before acting up again. Codes are showing misfires. After injector replacements, I did get a code for the Cat Converter one time but hasn't re-appeared. I'm several thousand dollars in and have the same result. The classic definition of insanity... Any thoughts from the group on this? Has anyone tried the Coolant Senor replacement and had the same effect as OP above? Any direction on next steps would be very helpful.

Welcome! Chasing the white rabbit down can be quite expensive. Trust me, I know. Have you tried cleaning or replacing your MAFs? Your ecu calculations will add/remove fuel according to your MAF sensor(s). I would highly recommend using paper air filter(s) and either cleaning both MAFs or replacing them with OEM MAFs. Denso MAFs are ok, but OEM is what you want.