Thank you. Will have this done as soon as possible.
when setting up, which four o2 sensors do I select? Theres a long list of options

 

oh wow they have added a ton more options than when I last played with it!

perhaps type in the word "Oxygen"

Your are looking for voltage reading for bank 1 sensor 1, bank 1 sensor 2, bank 2 sensor 1 and bank 2 sensor 2.

 

Thank you, I appreciate all the help. I will be back with results tomorrow

 

 

It’s good bet your fuel pump is going out, they need to provide specific pressure and volume at varying rpm’s and loads and a weak pump will still operate the car, but I. A lean condition, and with the ecu trying to add the difference at the fuel rail. U can borrow a fuel pressure gauge from AutoZone. Then you’ll find a large shrader valve on the fuel rail by the injectors, it’s pretty easy to see how much pressure is at the fuel rail. And compare it to the required factory specs.
A lean code is usually from either a leak in the intake somewhere between the MAF and the lower plenum, or low fuel pressure. It use to be that if the car started, then the fuel pump was working. But they have definitely become more precise as emission regulations have tightened and demand for better fuel efficiency has increased. Now it’s not unusual to trace a lean condition to low fuel pressure.

 

There is no shrader valve on the 3uz. Annoyingly....

To get a fuel rail reading on our cars you need a banjo style fitting where the fpd is on bank 2. Or cut and fit an inline fuel guage to the fuel hose.

 

Definitely looks like a fueling issue. What are the ST fuel trims at idle? MAF and O2's all look like they are reading correctly. I'd try to get a fuel pressure gauge installed inline and see what your pressure is at. They fuel pump is really easy to change on these cars as it lives right under the rear seat bottom that comes out with no tools required.

 

Ok so looking at the data we can tell a few things.

MAF and throttle position sensor appear to be working as normal
Coolant temp is working well too.

Oddities -
- the distance travelled seems to stop reading.... No idea on that one, but it doesn't matter in this case anyway.
- how were you accelerating without throttle between 13:59 and 14:02?
- The o2 sensors stop recording after 14:07 after the coasting finishes.

Most likely a data polling issue of the speed of the adaptor. However have to note this in context of the other data


So the LTFT's are very very positive.
O'2 don't get to approximate the right mix until you are were coasting.
The fact that it idles ok indicates there is some fuel but It is very much a lack of fuel problem. It doesn't look to be fuel injectors themselves judging from the fuel trims.

So we could be looking at any of or a combo of the following:
1. Kinked/twisted fuel hose (engine bay) - inspect, unkink, retighten
2. Something to do with the fuel pump relay / idle resistor circuit (heat sink on the strut tower in the Left hand side of engine bay). Perhaps the fuel pump relay isn't switching away from the idle circuit. You can easily bridge the connector to bypass the resistor. That removes that possibility from the equation.
3. Blocked fuel filter (in tank)
4. Slow/weak pump (in tank)
5. Faulty fuel pressure regulator (in tank)

The first 2 things are basically free to check.

A fuel pressure gauge can confirm if it is any of the last 3 items. Given the 3UZ doesn't have an easy to test valve, you will either need a banjo set up or cut in a permanent inline guage. I can't attach my toyota guide here for some reason but there is a pdf guide somewhere online for how to check the fuel system on these (or a tacoma or a landcruiser)

If it is confirmed fuel pump, filter or regulator related, replace them all as a module while in the tank.

Also from now on if you do other data collection runs you can drop the following sensors from the dashboard to allow for better data polling.
- distance travelled - (don't really need it for this)
- coolant temp (confirmed it works normally)
- throttle position sensor (confirmed it's reading fine too and the MAF follows it like it should)
- maf horsepower (duplicate of the g/second MAF graph - leave the g/s per second maf graphs there though as we need one to go off)

 

I rarely recommend a solution without doing all possible diagnostic to eliminate or confirm the problem and solution, however in this case, with a lean code, and an engine unable to clump above 3000rpms, I think it’s a very safe bet your problem is a lack of fuel pressure. Unless your on a tight budget and trying not to spend any extra money on your car, I think it would be wise to source out a replacement pump and/or sending unit and the entire fuel pump module if it’s in the budget. Just make sure to get a high quality unit that’s specifically designed for your car. Make sure to get the locking ring gaskets and strainer. I would suggest a Denso unit, unless you are on a tight budget and find an incredible deal on a Bosch or Walbro unit. Keep an eye on the arrival date and pull the old one out when convenient before the new arrives. There are multiple good videos on YouTube demonstrating how to remove and replace it. When you pull the old one, inspect everything and then compare the new one it arrives. If they are identical go ahead and complete repairing it. Once it’s back together clear your DTC’s and take it for a drive. I am confident your car will feel like new again. If it doesn’t, you’ll have narrowed down the culprits to a very few possibilities. And old fuel pumps are always a weak link. So even if it didn’t solve the problem, it is likely preventing other possible problems anyway.
This should fix your car, it’s not very expensive, or difficult and it is a good investment regardless. Go ahead and fix your car, good luck

 

I'd simply bypass the fuel pump resistor to increase the fuel pressure for the confirmation.

 

Thanks for this extremely useful information. To everyone else as well- thanks so much. I joined this forum to begin getting my car back in perfect shape and I would've never been able to even get to the point I'm at without the help of all yall.

I'm going to check all of this, watch some youtube guides, and get to fixing the fuel pump.

In terms of the data cutting out, I'm not really sure either. I think it might just be the obd2 sensor. I had issues with connecting to it previously (which is why I went and bought the wired one from Amazon instead). So connection issues could be the issue. Once I check the parts and if I go about replacing the fuel pump, I'll post some more data charts on my next trip.

 

thanks so much! I really appreciate this. extremely helpful. Definitely learned more about automotive repair from this forum than anywhere else.

I will post an update as I get the chance.

 

Yeah 'car scanner' app is the only app for a Bluetooth dongle that I found to work on the ls430. Took several attempts to find that app. I don't know why other apps can't seem to connect, despite using the exact same settings.

 

How did you go with bridging the pump resistor circuit?

How does the fuel supply hose look?

 

Which one do I bypass?
R2 or R3?

"R2 Circuit opening (Fuel pump (C/OPN))
R3 Fuel pump (F/PMP)"


edit:

I bypassed R2 by folding out the respective 85 pin (followed from a video). Started the car and rpms dropped from like 1000 down and it died right after. Folded the pin back into place and car started as expected. Not really sure if I did this properly since the relay looks different than most I've seen. I folded back the ground

Next I have ordered the fuel pump and am ordering a new filter assembly (233000A020) to replace at the same time.