Hello all. I'm honestly at a wits end, because every website I've posted to people just ghost me and doesn't respond and I have no idea what else to do to find what's going on.
Long story short my 07 ES350 with 132k miles runs lean, the max can be around 22% most recently on BOTH banks LTFT. I'm averaging 10-12 MPG in NYC. Most other people with this car can get 15-16MPG in the city. I discovered this problem when my car was having issues starting more and more as it warmed up while I was using it to work as a delivery driver
Here is a video when it was at it's worse, although generally it hasn't occurred much now and if it does, it's very brief delay.
This is the work that has been done or things that have been checked.
- Both upstream A/F Voltages around: 3.3V. Inducing a lean condition by disconnecting a hose makes them both go to 4.45-4.5V which is normal I believe. I did not induce a rich condition to test.
- Barometer: 100-101kpa @altitude 4m/13ft
- New OEM downstream O2 sensors
- New OEM Spark plugs
- Fuel pressure 1-2psi above spec, negligible
- DIY Smoke machine shows no leaks when putting smoke into intake. In fact, pressure builds and pushes smoke back out through my DIY smoke machine (smoke in jar, bike pump).
- New EGR Valve
- New oil cap o-ring
- Brake booster slight issue where pressing down and shutting the engine off, it immediately pushes back off, indicating a small vacuum leak. But pinching the hose and looking at the fuel trims shows its negligible. ALTHOUGH when the brake is in normal use, when I press the brake when the car is running, the short term on both banks can jump way high up to 20%, and then it raises the long term. Is that normal behavior?
- Measured resistances of 3/6 injectors - Cylinder 2, 4 and 6 all in spec. The other injectors are under the intake which makes it a pain to get to.
- NEW OEM MAF sensor because the original MAF sensor was underreporting, a junkyard MAF was underreporting, and the new MAF sensor OEM I got today is underreporting.
So at this point, I'm just looking for suggestions what else to do or check. I've been tackling this for 5 months now and honestly it's ruining my enjoyment of the car. I've only put 2500 miles on the car since I bought it last May.
I was told on scannerdanner that the needed percentages I had across all ranges (idle, 3000 RPM etc) were consistent indicating a fuel delivery problem? What do you all think? Like I wrote above I checked the fuel pressure. I noticed the last record this car has from Lexus at 120k miles says the dealer told the owner to do a MOC fuel system decarb, but the owner refused. It doesn't say why this was recommended.
I've brought it to an independent mechanic around 2 months ago, and they said they did not have these fuel trim problems when they checked and it was below 10% so they didn't want to charge me for an unnecessary smoke test. But when I got home and checked the fuel trims, they were near 20. I honestly got a feeling the shop wasn't interested in working on my car as they had a lot of newer cars that bring them more money (Porsche, new BMWS, Lexus', etc). Another shop the guy kept cutting me off jumping to things I wasn't even talking about so I didn't bother wasting my money there.
I've attempted to ask Scotty on his stream which he does reply to, unfortunately I cannot give all the info so he suggests stuff that I've already tried.
Thanks all.
2GR-FE engine
Here is a video when it was at it's worse
What am I supposed to be hearing /seeing?
my 07 ES350 with 132k miles runs lean, the max can be around 22% most recently on BOTH banks LTFT. I'm averaging 10-12 MPG
I see a few suspects ...
Measured resistances of 3/6 injectors
Resistance will tell you if it's burned out or not, but it doesn't tell you if it's sticking,or if they're clogged or spraying properly etc.
I've seen people go full backyard mechanic on this, and pull injectors right out along with the fuel rail and harness and test them outside the engine to observe spray pattern. It's not always possible though, so there are MANY other ways. A well trained and equipped mechanic can do something like hook up a pressure transducer or gauge and noid tester to the fuel rail, and watch the pressure change on his scope screen, and see if any injectors aren't delivering the same fuel as the others. SMA, SD and ETCG all have endless videos about testing fuel injectors.
the new MAF sensor OEM I got today is underreporting.
Please be more specific, what is it reporting at what engine load/speed?
If there is unmetered air getting in then that would certainly cause a lean condition.
Brake booster ... pushes back off, indicating a small vacuum leak ... when I press the brake when the car is running ... it raises the long term. Is that normal behavior?
So when you press the brake, the mixture goes lean. Well that's a smoking gun right there.
The brake booster is leaking vacuum.
you see the other air tightness checks it passes
but it didn't pass ALL the checks.
I checked the valve on the booster and it works.
alright so the valve works, but there's a leak. And the leak is probably after the valve, since the fuel trim only changes after you press the brake.
the MAF is still under reporting
And it will keep under reporting as long as there's a vacuum leak. That's what it's supposed to do.
I don't want to blow 800 on a new brake booster and get back to square one
Then test it. Start the car. Put the vacuum source tube in your mouth and suck, or use a syringe, your bike pump, smoke machine or whatever. Move the brake pedal up and down.
Will smoke enter the cabin at the pedals I assume?
There's a small chance, but it's more likely to come out under the hood since that's where the booster is.
can use a hand held pump and see if it holds PSI
It's not a good test. Neither is the smoke really, because the system is designed to hold negative pressure, not positive. Vacuum is sort of self-sealing.
Wouldn't disconnecting and plugging the hose replicate having a booster that is not leaking?
Yes in theory it would. So then why is the fuel trim changing when you press the brake? Unless the hose is leaking.
Maybe your vacuum leak is elsewhere then. I think I'm out of ideas.
Is it possible perhaps there are two leaks, but the booster could be the main one?
The video shows the failing for the engine to turn over.
I have all of Toyota's documentation:
So for the MAF
Engine off : Check if less than .56g/sec ✔️ Yes, result is .50g/sec
With Engine coolant temp temperature at 75C/167F:
MAF at idle : Between 3.2g/s - 4.7g/s while in Neutral ❌ No, result is 2.75g/s
Maf at 2500 RPM : Between 13.1 g/s - 18.9 g/s while in Neutral ❌ No, result is 10.7g/s
-> REPLACE MAF Sensor
As you see, it's hard to follow the documentation a bit as it's suggestions to replace things aren't always accurate but I get that's how it goes
For the booster, I'll show the tests and checks marking pass and x marking fail
INSPECT BRAKE BOOSTER ASSEMBLY
(a)Airtightness check.
(1)Start the engine and stop it after 1 or 2 minutes.
Slowly depress the brake pedal several times.
HINT:
If the pedal can be depressed to the floor on
the first time, but on the 2nd and 3rd time
cannot be depressed as far, the booster is
airtight. ✔️(2)Depress the brake pedal while the engine is
running, and stop the engine with the pedal
depressed.
HINT:
If there is no change in the pedal reserve
distance while holding the pedal for 30
seconds, the booster is airtight. ❌(b)Operation check.
(1)Depress the brake pedal several times with the
engine switch off and check that there is no
change in the pedal reserve distance when the
pedal is depressed.✔️(2)Depress and hold down the pedal, and start the
engine.
HINT:
If the pedal goes down slightly, operation is
normal -
The last one there I don't have an answer as not sure how much is considered slightly, or it means if it sinks really fast to the floor, etc. It can go down to the floor if I press it down but slowly if I hold it.
Anyways, yes you would suspect the booster, but the thing is as you see the other air tightness checks it passes. PLUS, I checked the valve on the booster and it works.
So what I've done is pinch off the line from the booster and checked if the fuel trims change, but they do not.
Here's the data recorded from this test. Note the fuel trims weren't as bad here.
Edit: I'm actually gonna see if the maf readings improve when I pinch off the hose. I'll report back.
Yes, but one of my points is it also showed the documentation for the MAF indicated a maf failure, meanwhile a new maf is in and it's the same issue. This was the same for the O2 sensors and other things, and I don't want to blow 800 on a new brake booster and get back to square one.
I just pinched off the brake booster again and sure, I see the short term fuel trims do not go up when the brake is pressed. BUT, the MAF is still under reporting at both idle and 2500 RPM. The short terms stood around 4-5% during this as well. What does that imply?
I pinched off the hose by disconnected the hose end from the valve and then plugging the hose.
I will attempt to smoke test with a DIY smoke into the booster. Will smoke enter the cabin at the pedals I assume? Or I can use a hand held pump and see if it holds PSI. Not sure how much PSI to pump it to.
Right, but by removing the supposedly leak by disconnecting the booster and plugging that hose off, why would it continue incorrectly reporting? Wouldn't disconnecting and plugging the hose replicate having a booster that is not leaking?
Hi. Here is the results I collected from tonight.I noticed the trims have been lower since I reset the computer, but I imagine as time goes on if I drive it will start raising again
Idle with brake booster:
STFT 1: 0.78%
LTFT 1: 7.03%
STFT 2: 0.78%
LTFT 2: 7.81%
Trim 1 Total: 7.78%
Trim 2 Total: 8.56%
2500 RPM with brake booster for 30 seconds:
STFT 1: -1.56%
LTFT 1: 5.47%
STFT 2: -1.56%
LTFT 2: 6.25%
Trim 1 Total: 3.91%
Trim 2 Total: 4.69%
Idle with brake booster disconnected and hose plugged:
STFT 1: 0.78%
LTFT 1: 7.03%
STFT 2: 1.56%
LTFT 2: 7.81%
Trim 1 Total: 7.78%
Trim 2 Total: 9.37%
2500 RPM with brake booster disconnected and hose plugged for 30 seconds:
STFT 1: -3.13%
LTFT 1: 0.78%%
STFT 2: -2.34%
LTFT 2: 4.69%
Trim 1 Total: -2.35%
Trim 2 Total: 2.35%
So yeah. First time I've ever seen long term go to 0, the short terms really started dragging the long terms down on the last test there.
I also did this test. Here is my video. Although I'm not sure if this test would work with mine because the one in the video doesn't have a valve, so I imagine the gauge cannot read the vacuum properly in the booster
Oh as to your comment on positive pressure, isn't the pump creating and showing negative, not positive pressure?