Curious where you guys would start on this one. I ran my 2005 LR3 out of gas, twice. (long story) Just prior to running out, it would spit out a 'reduced engine performance' on the dash.

So, first time, no issues afterword. The second time, I now have a code:
P0173-00 (AA) Fuel trim (bank 2)

I'm getting mixed results on where I'd start -- Injectors, o2 sensors, throttle body cleanings, etc. Knowing I ran it that low of fuel, I'm sure it pulled gunk from the tank. Fuel filter is built into the pump as I understand? If that was clogged, it wouldn't be simply "bank 2" I'd imagine though. So possibly gunked injector is where I lean to as a real possible problem.

Any thougths?

Dave aka Ghan

 

This is like when you go to the doctor and say "it hurts when I wrench my arm around like this," to which the doctor of course replies "well don't do that." Anyone can tell you running your LR3 even low on fuel is bad for the pump, not to mention running it out completely...

It's unlikely some gunk made it past the filter into an injector, if the filter got inundated with crap it just wouldn't pump or would burn out, it wouldn't pass gunk through it. Is the code for too rich or too lean? Too rich is typically easy to diagnose, but expensive to fix. Too lean is often hard to diagnose but cheap to fix. To start, clear the code and see if it comes back. If you have an IID tool, reset your fuel adaptations as well.

 

The gunk thing is a total myth - unless you somehow have floating gunk. The intake is at the lowest point, any gunk would have been taking into the filter regularly. The question is, though, did you do a hard reset of the computers after the incident? And you really need to not run out of fuel, more for the reason fuel keeps the pump cool and running dry a lot can shorten an older pumps life. Fuel is cheaper than an $800 pump.

 

So in Fairness -- The first time I ran out of fuel, I had a half tank left according to the gauge. That was in the summer of '18. This truck isn't my daily driver. As a matter of fact, it gets VERY little use, so I honestly forgot, a couple months ago, and it happened again. All told, I doubt I've put 1000 miles on since I first noticed it. Heck, I'd bet 5-600mi.

I do have an IID tool, I have cleared the code and it came right back within a few miles. I could reset the adaptions, but I read some people have done that and had their vehicle run worse.

As for hard reset -- You talking doing the positive to the negative for 15 mins or whatever it was?

Dave aka Ghan

 

Hard reset is just disconnecting the a battery lead. No need to connect them together, that is one old wives tale I wish would go away. The computers are polarized after all. But if you have the tool, you can do that too. I never heard about vehicle running worse. That should not happen unless there are existing issues like a bad MAF sensor. The transmission, apparently, thats another issue with an adaptation reset but a battery disconnect will not clear those.

 

It's stupid, and I agree -- but I think the theory of it is the 'capacitors' in the ECUs will discharge as current continues to flow, and dissipate. I was never really concerned if it was factual or not -- just disconnecting the Positive -- You're already basically there to put'em together, so why not. Again, do I think it needs it? no. /shrug

DaveM

 

Your truck might run worse for a very short amount of time until it re-learns the trims, but it should then run at least as well as it is running right now. Sounds like you don't have much to lose.

Did you figure out what was going wrong with your gauge? Are you completely sure you ran out of fuel and it wasn't some other issue? Seems suspicious...

Personally I do hold the positive/negative cables together for about 30 seconds (which I believe is specced by Land Rover, old wives tale or not). At least gives me the peace of mind that even if the issue persists, I did everything I could to discharge whatever energy is stored in the system. To each their own.

 

In the tank...wouldn't hurt.

 

Yeah. took a 5 gallon tank, then put in almost 20... definitely lower than 1/4 tank!

Dave aka Ghan

 

This.

Seems odd, I haven't heard of level senders going bad in these tanks, especially because I think there's more than one. I will say in terms of gunk in your tank that when I had my tank down last weekend, it was absolutely spotless inside - and it's the original tank, never opened (there was one cheeky shriveled up spider in the bottom of it, though, no idea how that guy got in). So unless you're filling up every time at Joe Shmo's Country Gas & Bait, your tank is also probably pretty clean.

My original question remains - is that a too rich or too lean code?

Simplest place to start - check your spark plugs, you may have fouled one in the death throes of running dry.