I have a 2011 is350 awd that just started having this issue today, I was backing out of a parking space and it stalled, I started it up again and it ran fine, then as I was on my way home it stalled again at a stop sign. I started it again and the cel and vsc lights were on and it would not go above 2000rpm, I limped it home and read the codes and got p0087 and p0174 which I believe are fuel rail pressure low and system lean

I am currently at 76000 miles, mods are intake, exhaust, rr racing tune

could this be a fuel pump issue? Anyone know how to test the pumps?

Any help is appreciated, thank you

 

Do you smell raw fuel in the engine bay? There is an open fuel rail recall right now with Lexus.

 

I didn’t notice any raw fuel smell when I opened the hood, I also can’t hear the loud ticking from the injectors anymore, but I also have a loud exhaust so maybe I just didn’t notice, but I always remembered having that injector tick

 

You can use a long wood dowel to the area or a long screwdriver to the ear. Off hand I wonder if the sensor connection failed.
One option is to use an app like Torque pro and you can see the data live. I know it is in there.

Do you have your own OBD reader? If so, look for HP fuel rail data. I think it ranges from 1900psi to 2800 or something like that.

That said another member just had to replace the sock filter inside the fuel pump as it was dirty and plugged. That shouldn't impact idle as much under load at rpm but water in the fuel could induce stalling.

I'd start with a MAF cleaning, filter inspection.
If the plugs are well aged, replace them.
Read codes and pressure at the HP rail.
Go from there.

 

Thanks, I do have a code reader, the codes are p0087 and p0174, the car runs and idles fine but is stuck in limp mode and won’t go over 2000 rpm

how can I test and see if the sensor connection failed? I don’t think my code reader will display fuel pressure

also the plugs have maybe 5k miles on them

 

In the Torque app (and likely Fusion app), it has a column for live data. Scroll down until you find it. It should be High Pressure Fuel data or something like that.
What I have seen is it was something like 1900psi at idle and went up to like 2600psi but don't quote me. I could be way off. Just that any rpm increase and it jumps up.
What app do you run?

 

I just have an obd scanner that also shows live data, it doesn’t give me fuel pressure, but I do see “fuel system 1” and “fuel system 2” on there and they both say closed, not sure what that means

 

I'm guessing it doesn't change when you start it?
I'll try to remember to connect and see what the labels are. I'll post back later.
You could order an elm327 bluetooth. They are like $20 or less. Download the app and have another tool.

 

that is with the car idling. i did a little more testing yesterday where i unplugged the fuel pump in the tank, and the car did not start, so obviously it is getting fuel from that pump, i also unplugged the high pressure fuel pump and started the car, nothing changed except the addition of a low voltage code for the high pressure pump which i am assuming is a result of the plug being disconnected. I'm leaning towards a bad high pressure pump, does anyone have any info on how hard it is to replace that pump?

 

We have some high mileage vehicles on here and few report HP pump failure. The sensor on the HP fuel rail does fail tho. Several unplug it to change the code just like you did on the other part. You might try that but I would want to know the pressure reported by that sensor first.
Has this vehicle had the fuel rail recall done?
They won't do it with an error code present.

 

The recall has not been done, I ordered a cable to hook my laptop to the obd port so I can use Techstream and try to get the pressure from there, how hard is it to replace the sensor, and would that cause the symptoms I’m experiencing

 

Not the expert on this but I think you need to know and it will cause this.
PS - I'd drop the $20 on a wifi or bluetooth obd unit too. You can gather info pretty quick. Techstream has its uses and it is a must have but this also has benefits of quick easy on the fly data collection.

In Torque Pro I had to add a gauge to see it.
At warm idle: 530psi
Near R/L under load: 2,050psi

 

Is there a torque pro alternative for iOS? Or one I can use on my laptop? I should have the usb obd cable today.

Luckily this is my second car so I can take my time and properly diagnose it before throwing parts at the problem

 

Just looked; the obd-fusion app will do the trick for iOS.
This AM cold start at 32°F and fuel pressure was 2150psi at cold idle (1,150 RPM). Who knew!

 

I got the car hooked up to Techstream today, it wasn’t a cold start since my coolant temp at the time was 127 degrees, 900rpm idle speed

my fuel pressure reading was 605psi

is this normal? If it is does that indicate a bad fuel pressure sensor?