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Hi all, this is my first post here. Thanks in advance for any help. As stated in the subject I have a non-starting is250 that threw a P050B code. It started 10 days ago, I went to Europe, came back, and now it doesn't start. Battery is good, visual inspection of the engine doesn't show any obvious wiring issues, and I have never had any starting or running problems prior to this. It's my daily driver. 180,000 miles. When I arrived home from my trip it "tried" to start. I could hear it trying to fire a bit, but then it progressively lost even that "firing" sound. Any advice would be appreciated.
Hi all, this is my first post here. Thanks in advance for any help. As stated in the subject I have a non-starting is250 that threw a P050B code. It started 10 days ago, I went to Europe, came back, and now it doesn't start. Battery is good, visual inspection of the engine doesn't show any obvious wiring issues, and I have never had any starting or running problems prior to this. It's my daily driver. 180,000 miles. When I arrived home from my trip it "tried" to start. I could hear it trying to fire a bit, but then it progressively lost even that "firing" sound. Any advice would be appreciated.
How old is your current battery? Id get it load test it if you can.
UPDATE: Cleaned MAF sensor, cleaned throttle body, replaced 3 spark plugs (since I was already on that side removing the throttle body), cleaned the PCV valve until I could hear good movement inside by shaking it), I can hear the fuel pump priming while I turn on the push-button, I sprayed starter fluid in the intake tube and tried starting. All of this resulting in no difference in its starting attempts. It sounds like the engine has compression (not surprised because it ran well when I parked it). So I'm guessing spark is not occurring at any of the cylinders. Not sure where to go next.
UPDATE: Cleaned MAF sensor, cleaned throttle body, replaced 3 spark plugs (since I was already on that side removing the throttle body), cleaned the PCV valve until I could hear good movement inside by shaking it), I can hear the fuel pump priming while I turn on the push-button, I sprayed starter fluid in the intake tube and tried starting. All of this resulting in no difference in its starting attempts. It sounds like the engine has compression (not surprised because it ran well when I parked it). So I'm guessing spark is not occurring at any of the cylinders. Not sure where to go next.
I was going to comment on flooded engine, but you beat me to it. Try holding the gas pedal down while trying to crank. I'd say try no more than a few times.
Another is pull one of the easiest plugs on bank 1 and see if it's wet.
I was going to comment on flooded engine, but you beat me to it. Try holding the gas pedal down while trying to crank. I'd say try no more than a few times.
Another is pull one of the easiest plugs on bank 1 and see if it's wet.
Just pulled spark plug from cylinder 1, not wet, looks normal.
I was going to comment on flooded engine, but you beat me to it. Try holding the gas pedal down while trying to crank. I'd say try no more than a few times.
Another is pull one of the easiest plugs on bank 1 and see if it's wet.
I also tried messing with the gas pedal while cranking, it didn't change how it behaved at all during cranking.
I also tried messing with the gas pedal while cranking, it didn't change how it behaved at all during cranking.
Do uou have a scan tool to use on OBD port? See if it reads, or has communication error. If it won't communicate then it might be a bad fuel pressure sensor.
Do uou have a scan tool to use on OBD port? See if it reads, or has communication error. If it won't communicate then it might be a bad fuel pressure sensor.
Ok. Can you reset the code, and the car will try to crank? Also if your scan tool does live data. What temperature is the coolant sensor at?
I reset the code. Nothing changed. Yes it cranks well, but with no firing. I think it does have live data, but I don't remember the temperature reading. This is Southern California, it's currently 66 F.
I used a more advanced scan tool on the car. It has no engine fault codes at this time. I had cleared the P050B code, but nothing else comes up. It reads sensors live. 76 degree F coolant, approximately 3100 psi fuel pressure, 18% throttle position voltage, ...etc. I don't know why it won't start. I even tried removing the intake, holding the throttle body flap partially open with a rubber tool, spraying starting fluid behind the flap, and attempting to start. It still sounds like it is really uninterested in starting, no sputtering or anything really. I checked spark by removing a plug, keeping it fixed to a coil, touching the threads to metal, and watching it spark while cranking (all new plugs), spark was good. I thought maybe a timing problem, so I changed the crankshaft position sensor. Still no luck. I'm completely stumped.
I used a more advanced scan tool on the car. It has no engine fault codes at this time. I had cleared the P050B code, but nothing else comes up. It reads sensors live. 76 degree F coolant, approximately 3100 psi fuel pressure, 18% throttle position voltage, ...etc. I don't know why it won't start. I even tried removing the intake, holding the throttle body flap partially open with a rubber tool, spraying starting fluid behind the flap, and attempting to start. It still sounds like it is really uninterested in starting, no sputtering or anything really. I checked spark by removing a plug, keeping it fixed to a coil, touching the threads to metal, and watching it spark while cranking (all new plugs), spark was good. I thought maybe a timing problem, so I changed the crankshaft position sensor. Still no luck. I'm completely stumped.
How were you able to get to the Crankshaft sensor? It's located bhind the AC compressor.
Here's the diagram of all the senthese on the 4GR engine: I'd start with OHM/ check resistance on the camshaft sensors/damaged wiring. Another is yoy fuel pressure is reading 3100 psi off the bat. Even at WOT it should be around 2000psi, anf 600 psi idle.
Leading to believe a malfunction fuel pressure sensor. It's weird that if it was the ECU wouldn't communicate with a scan tool. This is a first on the code It's very rare
How were you able to get to the Crankshaft sensor? It's located bhind the AC compressor.
Here's the diagram of all the senthese on the 4GR engine: I'd start with OHM/ check resistance on the camshaft sensors/damaged wiring. Another is yoy fuel pressure is reading 3100 psi off the bat. Even at WOT it should be around 2000psi, anf 600 psi idle.
Leading to believe a malfunction fuel pressure sensor. It's weird that if it was the ECU wouldn't communicate with a scan tool. This is a first on the code It's very rare
Forgive the auto corrections man. I'm constantly having to edit.
I changed the crank sensor by yes, removing the AC compressor, changing the crank sensor, and reinstalling the AC compressor. I have also tried unplugging the fuel pressure sensor, which from what I understand, will bypass the sensor if it is the problem, allowing the car to start. It also did not work.
Also, speaking to a Lexus mechanic, he said that having a faulty camshaft (not crank, but cam) will not prevent the car from starting. So I haven't been worrying about the cam sensors.
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2009 IS250 won't start and has code P050B
Try holding the gas pedal down while trying to crank. I'd say try no more than a few times. 
