1-Yr Check-in and Trouble Code Rant

Lakeray

Member
Joined
May 6, 2019
Posts
8
Reaction score
3
Location
OKC
Love your adventures!

Anybody hear anything on the parts for the recall will be available?
 

CRYA

Full Access Member
Joined
Apr 14, 2021
Posts
217
Reaction score
121
Location
Napa Valley
Yep awesome pics! I just hit 1-year with mine too, but yeah, I don't got time for those awesome pics. I added some from our EMHT trip. Definitely check it out, starts out of Needles.
 

cjm41

Well-Known Member
Joined
Jun 12, 2021
Posts
47
Reaction score
40
Location
San Diego, CA
There was a TSB on the p0089 code that was being fixed with a software update. I had it done, but I’ve always been a bit suspicious of that fix - thinking it might have just introduced a little tolerance for a slowly failing low pressure pump. At any rate, that TSB is out there somewhere.

The other thing you can try checking is your fuel trims. If you have a low fuel pressure condition, I would expect high positive fuel trims. Check at idle and at steady rpms at two higher levels (e.g., 1500 and 2500 RPM).

As for the fuel smell, might check your fuel line junctions in the engine bay - make sure there isn’t a little leak someplace. A really badly leaking injector can give you some fuel smell, but kind of doubt that‘s the issue here. Smoke on startup? Other than that pump flange, a leak in the evap system someplace can give you fuel oder, but should also through a code for an evap leak (and CEL).

I went out and did this and didnt find any anomalies that jumped out at me.

There was a short term and long term fuel trim banks.

The short terms sat around 2% at idle, dipped down to -10% or so as the RPMs go up.

Long terms did the same, just at a higher percentage (of what these percentages are, I don’t know).

I also took the truck for a drive last night and tried to find any semblance of hesitation or anything that would indicate a fuel problem. I’m talking like floor it from a red light, floor it getting on the highway on-ramp up to about 80. Perfectly smooth.

Unless you see something here, I think my next step is to drop the gas tank to both investigate the fuel smell and see if there is something wrong, another crack, maybe something came loose, etc.

If I don’t find anything there, I think the first part I’ll replace is the Fuel Pressure Sensor (LR108241). It’s only about $100.

Any thoughts on the attached?
 

Attachments

  • 323A44F9-9072-474D-A935-68B253EAB653.jpeg
    323A44F9-9072-474D-A935-68B253EAB653.jpeg
    45.6 KB · Views: 8
  • 3551CCD6-2200-4696-A82C-D00529B45232.jpeg
    3551CCD6-2200-4696-A82C-D00529B45232.jpeg
    47.4 KB · Views: 9

jlglr4

Full Access Member
Joined
Mar 19, 2019
Posts
770
Reaction score
397
Location
Northern California
The only good way to read fuel trims is to run both short and long term simultaneously for both banks along with RPMs. So, five fields: short term bank 1, long term bank 1, short term bank 2, long term bank 2. Then, hold it steady as you can for 20 seconds or so at a few different RPM levels: idle, something around 1500, something around 2500.

If your overall (short+long) trim is negative, the engine is running rich. If positive, its running lean. By looking at the trend as RPMs increase or decrease, you can sometimes get a better picture of what’s going on (e.g., positive fuel trims at idle that tend to zero out at higher RPMs points to a vacuum leak; fuel trims that get more positive as RPMs increase might point to a fuel starvation issue, or MAF issue; rich conditions might be a fuel injector; etc.).

So, these graphs are not ideal, but your long term graph is way positive, indicating a lean condition. When you accelerate, looks like it comes down. Short term always jumps around a lot while driving (which is why steady RPMs are easier to read), but looks like short term is also dipping when you hit the gas. So, more than likely, you have a vacuum leak of some kind (vacuum is highest at idle, and air flow is at a minimum, so a vacuum leak shows up more at idle and evens out as you throttle up). But it would be good to run that data again at steady RPMs.

If the tank is leaking air, that could be the source of a vacuum leak through the purge valve.
 

cjm41

Well-Known Member
Joined
Jun 12, 2021
Posts
47
Reaction score
40
Location
San Diego, CA
The only good way to read fuel trims is to run both short and long term…
This is great info. I really appreciate this. I’m going to take a short day tomorrow and really dig into this using the info you’ve provided.

I’ve been dreading dropping the gas tank because it’s full (like maybe 20 miles driven since it was topped off) but I’ve got a bad feeling about that plastic part that the fuel pump attaches to is failing (or the gasket is). I remember putting it back on feeling like it was seated a bit weird because it was a real pain to put back on without the special tool.
 

djkaosone

'11 LR4 HSE LUX 5.0L V8
Joined
Oct 26, 2015
Posts
732
Reaction score
455
Location
SoCal
The only good way to read fuel trims is to run both short and long term simultaneously for both banks along with RPMs. So, five fields: short term bank 1, long term bank 1, short term bank 2, long term bank 2. Then, hold it steady as you can for 20 seconds or so at a few different RPM levels: idle, something around 1500, something around 2500.

If your overall (short+long) trim is negative, the engine is running rich. If positive, its running lean. By looking at the trend as RPMs increase or decrease, you can sometimes get a better picture of what’s going on (e.g., positive fuel trims at idle that tend to zero out at higher RPMs points to a vacuum leak; fuel trims that get more positive as RPMs increase might point to a fuel starvation issue, or MAF issue; rich conditions might be a fuel injector; etc.).

So, these graphs are not ideal, but your long term graph is way positive, indicating a lean condition. When you accelerate, looks like it comes down. Short term always jumps around a lot while driving (which is why steady RPMs are easier to read), but looks like short term is also dipping when you hit the gas. So, more than likely, you have a vacuum leak of some kind (vacuum is highest at idle, and air flow is at a minimum, so a vacuum leak shows up more at idle and evens out as you throttle up). But it would be good to run that data again at steady RPMs.

If the tank is leaking air, that could be the source of a vacuum leak through the purge valve.
That's some good info right there. I've been battling rich fuel for quite (3 years) a while and still can't figure it out. When I did my timing chain, I replaced a lot of fuel related things hpfp, injectors, all o2 sensors, both maf sensors, map sensor, and still shows negative fuel trims. I gave up, but might have to check for vacuum leaks again.
 

jlglr4

Full Access Member
Joined
Mar 19, 2019
Posts
770
Reaction score
397
Location
Northern California
@djkaosone Vacuum leak won’t cause a rich condition, it will cause a lean condition.

A vacuum leak allows unmetered air into the system, so the fuel ratio goes lean. To battle the lean condition (too much air, not enough fuel), the fuel trims will go positive (adding fuel) to try to get back to the optimum air/fuel ratio.

Rich conditions are caused by not enough air or too much fuel. So, the fuel trims will go negative to reduce the amount of fuel and get back to the optimum ratio.

If you’ve got a rich condition, aside from injectors dumping too much fuel, I think you’re mainly looking at sensors. Looks like you’ve replaced the most common suspects, but the two you don’t mention replacing are the coolant temp sensor (two actually) and the fuel rail pressure sensor. Either one could throw you rich (or lean) depending on which direction they’re off.

The other thing that comes to mind is the purge valve. A bad purge valve can give a rich or lean mixture depending on what‘s in the charcoal canister. If the canister is rich and that purge valve is opening when its not supposed to (i.e., if its leaking and not closing when its supposed to), that can give a rich fuel mixture as well.
 

cjm41

Well-Known Member
Joined
Jun 12, 2021
Posts
47
Reaction score
40
Location
San Diego, CA
Yep awesome pics! I just hit 1-year with mine too, but yeah, I don't got time for those awesome pics. I added some from our EMHT trip. Definitely check it out, starts out of Needles.
I remember your truck and username. I purchased my truck on April 20th of last year and you posted about your purchase around the same time. That color is amazing. I love the grey and I’m happy with it, but every time I see a Firenze one I get a little jealous haha
 

Tbh1981

Full Access Member
Joined
Aug 30, 2020
Posts
82
Reaction score
29
Location
Ontario
I come for the Land Rovers. I stay for the technical discussions.
 

cjm41

Well-Known Member
Joined
Jun 12, 2021
Posts
47
Reaction score
40
Location
San Diego, CA
If the tank is leaking air, that could be the source of a vacuum leak through the purge valve.

I believe the tank is leaking, at the dust cover gasket. I’ve been dreading dropping the tank so I bought a boriscope. Got under there today and found what appears to be a wet area near the base of where the dust cover attaches to the tank.

What I believe I’m seeing is a wet area created when the tank was full a couple weeks ago. Now it’s about 3/4 full so the fuel doesn’t have the opportunity to escape.

However, I’m still smelling fuel while the truck is running (and not so much with it off like I was a week ago)… which would corroborate my theory. When the fuel level was high, that puddle was fresh, and would allow me to smell it. Now that the fuel level is lower, fuel-filled air is escaping there, which makes sense why it’s only really noticeable while the truck is off and it’s not adding tot the semi-fresh, slightly aging wet spot.

This would create a vacuum leak, which would cause bad air/fuel readings tripping the sensor and subsequently triggering a trouble code.

I feel confident dropping the tank is not a waste of time. I will have a new gasket and proper wrench (instead of hammering it back into place like I did last time).

Now the big question is… do I go ahead and replace the fuel pump while I’m in there, being that I’m at 87k miles. I’m thinking for $110 I just knock it out. It adds almost zero time to the project.
06058716-C5F1-4C32-BCB2-BDB5792CCD86.jpeg
 

Latest posts

Forum statistics

Threads
35,409
Posts
208,392
Members
29,706
Latest member
Schildy
Top