Weird Stall and rough running on my LX570

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cek347

cek347

Joined
Sep 22, 2016
Threads
8
Messages
70
Location
SE PA
Hi all, New to me LX570 has been awesome this last month. Just took about a 600 mile round trip out to a cabin fully loaded with gear and 4 people. Ran great, comfortable, and got decent MPGs (19.7) for the trip. After my first fill up a few weeks ago, I noticed it only took about 17.7 out of the 24.6 its supposed to have. A quick search shows that is normal and the tank leaves about 5ish gallon reserve and I wasn't quite on E yet. Fast forward to me coming home and looking to get closer to E since I have about $.70 off a gallon at Sunoco with my gas reward points (from my grocery store). My gauge was sitting above E just below an eighth of a tank mark as I headed over to family for Easter. As I was leaving their house the truck just shut off in the driveway. Immediately started back up and was idling fine. Started driving home and about 1/4 mile later started sputtering and died on the side of the road. After a minute of me contemplating my selling of my '21 5th gen with only 37k miles on it, it started back up and made it another 1/4 mile and died again. Started again and was able to get the last little bit home (another 1/4 mile). Backed in the driveway and it died again. Put the code reader on it and P0171 (Lean bank 1) and whatever the code is for bank 2 ( Lean bank 2). The only thing that came to mind was a fueling issue due to low fuel but I know it still had 5-6 gallons left. Ran out to the gas station in my wife's car with my 2 gallon can, came back and put it in. Started up and was idling fine. Ran the code reader and no codes..... Headed over to the gas station and filled up (16 gallons), no issues at all, ran fine the last 30-40 miles without any issues and not codes.

Anybody have any thoughts? Why would it stall out with 5-6 gallons left? Was it a fluke that adding gas fixed it? I'm going to fill up at a 1/4 tank for now but I'd like to figure out why I can't access that last 5-6 gallons without stalling.
 
Parked on an incline? Fuel pump might have been starved...like really lean.

I recommend using fuel in all internal combustion vehicles. Fill er up and see if the problem comes back. If so, check fuel, check spark. Check MAF.
 
I think it just ran low on gas. You’re pretty brave to rely on the gas gauge, especially with just your one data point from a previous fill up and especially with an unfamiliar truck. I suspect you’ll be fine if you don’t run it to E.

What’s the reference to selling a 5th gen ‘21?
 
Does sound like a fuel issue. Several potential causes.
  1. Fuel pump. Fuel pumps have been known to go out. Some model years have had recalls, but peripheral model years can definitely be affected.
  2. Fuel driver. Has also been known to fail.
  3. Fuel level sender. Can fail and potentially show low fuel remaining when it's actually out of fuel.
Based on your symptoms, I would suspect number 3. You can confirm by how much fuel you can add including the 2 gallons you tossed in.

Recommend fix by changing the whole fuel pump/fuel float assembly which includes the fuel pump, which is a liability into higher miles.

It's typical to run down to the fuel light before looking for gas. Usually has 3-4 usable gallons remaining in a properly working rig.
 
CanadianRockyCruiser said:
Parked on an incline? Fuel pump might have been starved...like really lean.

I recommend using fuel in all internal combustion vehicles. Fill er up and see if the problem comes back. If so, check fuel, check spark. Check MAF.
Click to expand...

Having owned two GXs and two 100s, I for sure know this beasts need plenty of fuel for combustion. Ill keep it filled up when I hit a quarter of a tank for now. Going to get a can of MAF cleaner and give it a rinse.

Sandroad said:
I think it just ran low on gas. You’re pretty brave to rely on the gas gauge, especially with just your one data point from a previous fill up and especially with an unfamiliar truck. I suspect you’ll be fine if you don’t run it to E.

What’s the reference to selling a 5th gen ‘21?
Click to expand...

I filled it up once when it was close to E and it took a bit over 17 gallons which prompted me to search and find these 200s E on the guage usually means it had 4-5 gallons reserve. That lead me to believe I was good to go. I apparently am not.

The 5th gen reference was because my 5th gen was perfect and going to an older truck with 90k more miles comes at a risk. When the whole family was in the LX stalled out and my wife stared at me, thats what went through my head.

TeCKis300 said:
Does sound like a fuel issue. Several potential causes.
  1. Fuel pump. Fuel pumps have been known to go out. Some model years have had recalls, but peripheral model years can definitely be affected.
  2. Fuel driver. Has also been known to fail.
  3. Fuel level sender. Can fail and potentially show low fuel remaining when it's actually out of fuel.
Based on your symptoms, I would suspect number 3. You can confirm by how much fuel you can add including the 2 gallons you tossed in.

Recommend fix by changing the whole fuel pump/fuel float assembly which includes the fuel pump, which is a liability into higher miles.

It's typical to run down to the fuel light before looking for gas. Usually has 3-4 usable gallons remaining in a properly working rig.
Click to expand...

Im going to keep it filled up beyond a quarter tank and monitor for now. Ill keep a fuel pump replacement on my to do list. I put in a total of 18 gallons when it was just above E, no reserve light.


Thanks guys. Hopefully that is the only issue.
 
cek347 said:
Im going to keep it filled up beyond a quarter tank and monitor for now. Ill keep a fuel pump replacement on my to do list. I put in a total of 18 gallons when it was just above E, no reserve light.
Click to expand...

That's not how these trucks work and there's something wrong to be fixed to avoid future frustration and dissatisfaction with the LX. Having to keep the gauge above a quarter tank would mean poorer range than the already mediocre range on a heavy truck. It's very possible your truck has a failing fuel pump or ECU that you'll want to keep an eye on. How many miles?

Here's some more info

TeCKis300

Thread '500 Mile Range and Tank to Empty Test'

20190118_131221.webp

513.9 miles to bone dry empty. With my larger 33” tires, the actual corrected driven range is 544 miles.

To be clear, this range is with a recently installed LRA 12.5 gallon sub-tank. Roughly 70% highway, 30% local mix.

I also did a test as I had an external fuel can with me. I ran my main tank and aux tank dry to engine stall, to test how much actual range there is when the low fuel light comes on – 45 (local) miles.

The theoretical capacity is 24.6 gallons main tank and 12.5 gallons auxillary, for a net capacity of 37.1 gallons. Full up empty, I pumped 35.13 gallons...
  • Like

TeCKis300

Thread 'P0171: System too Lean (Fuel Trim)'

Working through this and could use the hive minds support. P0171: System too Lean (Fuel Trim). Also P0300: Random/mulitple Cylinder misfire detected. Multiple specific cylinder misfires P030x.

Symptoms: In diagnostics after getting home. LT fuel trim on both banks at idle are high. +15 and +18. LT trims are only incrementally elevated at higher engine speeds/loads (+4/+4 at WOT), so trim is inversely proportional to load. Initial suspicion is a vacuum leak, but didn't find any in cursory troubleshooting. Cleaned MAF and is not the issue. LX570 is a 2009 with...

SeaHunt

Thread 'PSA: Stranded….Fuel Pump ECU'

2013 with 130k; was driving 40 MPH, and truck died. Luckily had a nice pullout and was only 2 miles from a dealer. Heard back today that it’s the fuel pump control module. I asked if they have done many and he said uncommon on the 200 but fairly common on the Tundra, which I assume is simply the sample size is much larger. I’m the original owner and this is the first real issue.

Posting this as I was fairly certain I had a fuel issue as the truck cranked no problem, but could not find anything online. This would have been a real problem in a lot of the areas of Maine this truck goes...
  • Like
 
cek347 said:
Hi all, New to me LX570 has been awesome this last month. Just took about a 600 mile round trip out to a cabin fully loaded with gear and 4 people. Ran great, comfortable, and got decent MPGs (19.7) for the trip. After my first fill up a few weeks ago, I noticed it only took about 17.7 out of the 24.6 its supposed to have. A quick search shows that is normal and the tank leaves about 5ish gallon reserve and I wasn't quite on E yet. Fast forward to me coming home and looking to get closer to E since I have about $.70 off a gallon at Sunoco with my gas reward points (from my grocery store). My gauge was sitting above E just below an eighth of a tank mark as I headed over to family for Easter. As I was leaving their house the truck just shut off in the driveway. Immediately started back up and was idling fine. Started driving home and about 1/4 mile later started sputtering and died on the side of the road. After a minute of me contemplating my selling of my '21 5th gen with only 37k miles on it, it started back up and made it another 1/4 mile and died again. Started again and was able to get the last little bit home (another 1/4 mile). Backed in the driveway and it died again. Put the code reader on it and P0171 (Lean bank 1) and whatever the code is for bank 2 ( Lean bank 2). The only thing that came to mind was a fueling issue due to low fuel but I know it still had 5-6 gallons left. Ran out to the gas station in my wife's car with my 2 gallon can, came back and put it in. Started up and was idling fine. Ran the code reader and no codes..... Headed over to the gas station and filled up (16 gallons), no issues at all, ran fine the last 30-40 miles without any issues and not codes.

Anybody have any thoughts? Why would it stall out with 5-6 gallons left? Was it a fluke that adding gas fixed it? I'm going to fill up at a 1/4 tank for now but I'd like to figure out why I can't access that last 5-6 gallons without stalling.
Click to expand...
Sounds like you need a new sender. They usually fail showing around 1/4 tank, but the tank is truly empty.

I would replace the pump at the same time the sender is being replaced since the labor time is identical.
 
I'm guessing my best course of action is to run a fuel pressure test and get some data. I'll have to pick up a kit for Toyota.

Reading the one quoted thread above, I will find the fuel pump ecu, disconnect it and clean the connectors with electric contact cleaner.

I do have a Bluetooth OBD dongle and the torque app, so I can get readings for other data if are any other suggestions.
 
Well, I went ahead and bought the complete fuel pump and sender 77020-60342, pump assembly seal in case the assembly doesn't come with one 77169-02050, and a new gas cap 77300-06040 because it's probably close to time anyway. Someone mentioned Fred Anderson Toyota of Asheville having 25% off their already discounted parts and free shipping. I didn't want to miss out on that deal so I pulled the trigger. Total for all 3: $385.33. I'll wait until the tank gets low in a few weeks and drop it.
 
You may want to buy one of the Amazon fuel tank tools to remove/install the retaining ring.

The pump doesn’t come with the large o-ring.

Be careful with the pump harness, it’s short and you don’t have much room.

The yellow retaining clips on the fuel lines (on the tank/pump side) have to be pulled completely out to remove the lines.

Blow off/clean off the top of the tank really well before starting work to get dust and pebbles out of there.
 
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