2008 Rx350

I changed the coils and plugs yesterday. Cleaned the throttle body etc. I originally thought I may have clogged something or sprayed to much cleaner. So I let it sit overnight after the initial start /stall issue.
Today.. When I went to start the car, it starts up like normal then stalls unless I keep depressing the gas pedal over 3k rpm. The only thing I could find online the was idle control valve (which I believe is electronic in my car), which could replicate this same issue.
I rechecked all the vacuum hoses, unplugged the battery, etc still nothing. When the car starts.... all check engine lights are clear, when it stalls i see check engine, battery, and oil light temp on.. When i hook up to OBD scanner, no codes!!

Im stumped, any advice help anything would be so appreciated.
Thank you

Alex

 

check for any air leaks on throttle body , inlet manifold etc and check vacuum hoses for leaks.

 

isnt’ it that when your engine stalls when the key is still on is like you putting ur key to on but not starting the car, hence the lights.since u change plugs and coils, maybe problem is there.did u use quality plugs?if everything else fails and you don’t have any where else to go, i suggest putting back the old coils and see what happens.i know it’s a lot of work but just pitching an idea

 

I had the same issue after plugs replaced,it was the the pressure hose under the intake manifold to PCV valve not connected properly

Check your hoses

 

Throttle body actuator may messed up during cleaning, Try reset ECU or disconnect battery.

 

See if the MAF sensor is connected properly.

 

Any update/answer/other help on this thread?

I have a 2008 RX 350 in the same pridicament. It's got 150K miles and began doing the same thing as described in this thread- after swapping out plugs and coil packs, engine turns over for a few seconds, but then stalls.

Background:
Originally decided to swap out all the plugs and coils because it started idling roughly at a stop one day, then thru VSC engine code. Then at home I checked the OBD and it thru a code for one of the coil packs (#5, back center driver side). Upon checking coil packs they were the older packs so I decided to change them all out and swap out plugs too.

Went to Lexus dealer and bought OEM plugs and coil packs. New plugs are the same part # that were in the engine: 9091901247 . The new coil packs are part # 90919A2007 , which the dealer says replaced the original ones that the engine had: 9091902251.

Installed the new plugs and coil packs, reconnected everything, then went to start her and she just starts for a few seconds then just stalls, over and over and over again!

This is what I've done, and it still is stalling:

1. I've reset the ECU, EFI, ECTM by disconnecting battery and using the fuses.
2. Cleaned the throttle body intake and MAF sensor thoroughly (I even bought a new throttle body and installed it and still stalled)
3. checked the gaskets for throttle body intake and plenum, they're both good
4. Replaced a breather hose from the plenum to the PCV valve cause it was cracked.
5. Have triple checked all vacuum lines and electrical plugs and they're all connected as should be.
6. Have triple checked the connections of the coil packs and they were done right

The engine fires right up and for a few seconds sounds like it will run right but it just shuts off.

These are things I haven't done:

1. Inspect the fuel pump
2. Change out all fuses
3. Reconnect it all back to the way it was and see if it still does it
4. Swap out the Camshaft position sensors
5. Swap out plenum
6. Inspect swap out alternator
7. ???

Any one have any other ideas?

Please help!!!!!!

 

how about fuel pressure?since it would start right up and then stall.so spark would be present i presume?and if it start every time and stall after, could be clogged/leaking fuel line?or fuel pump is starting to die?

 

Thank. you Marwin! I was thinking about that but seems too much of a coincidence for that to go out after only disconnecting the battery and swapping out plugs/coil packs.

It's now throwing the following OBD fault codes:

1. P0121- Throttle position (TP) switch A/ accelerator pedal position (APP) switch A - range/performance problem [Lexus: Accelerator Pedal Position Sensor / Throttle Position Sensor A Range/ Performance]
2. P0123- Throttle position (TP) switch A/ accelerator pedal position (APP) switch A - high input [Lexus: Accelerator Pedal Position Sensor / Throttle Position Sensor A Circuit High Input]
3. P2135- Throttle position (TP) or accelerator pedal position (APP) sensor/switch A/B - voltage correlation

Note: I thoroughly cleaned throttle body intake, and even replaced it with another one that came out of a Lexus with 30K on it (same exact part number). But it is still stalling after a few seconds of being on and sounding fine. I can hold the pedal down and rev up the engine for a little longer but it still stalls.

I added a video file so you can see/hear what I'm dealing with:


Anyone know how to reset the throttle position or accelerator pedal position sensor/switch? Or where they're located so I can check them? Thank you!

 

UPDATE:

I let the car sit overnight, cleared the ECU then ran the OBD scanner again and got fault code P0368, a problem with camshaft sensor B on bank 1 (behind the plenum, in between coil packs for cylinders 3 & 5).

So... I let the car sit for a 3-4 hours more, then cleared the ECU again and ran the scanner to confirm P0368, and it came up again. Double checked the harness wires to camshaft sensor B and they look good. Headed out to dealer tomorrow morning to get camshaft sensor (part # 90919-T5005 [replaced 90919-05060, Denso 1290]).

Will post results.

 

Hi Lexban, I have some info on this but I have to go thru it. There is a harness connector in that circuit but need to look thru my book to find location for you and see what else.
But I have to ask was the positive terminal shorted or sparked to ground? Plz be honest and anything else you can think of can help.

 

9/10 times after doing a tune-up on these, the Cam sensor connector wires will get stretched if not unplugged.
Please take a closer look at that before deeming the sensor bad.
These sensors are pretty robust.

 

Just saw your update did your old codes P0121, P0123, and PP2135 go away or is the Cam code added to this now?
If so nad1370 nailed it. There is an overlap in the circuit thru splices to throttle position and towards ECM. Plz consider detail below.



Here are some ECM Ground Points that may be loose located at ED and EE.

 

Thank you both for the reply. Very helpful (the schematics!). Compromised wiring makes the most sense, but I can't discount a faulty sensor which could have triggered VSC warning light and code P0355 in the first place.

I double checked the wiring and wire harness but still have had no luck. I will go ahead and do that again (will be a lot easier with diagram!). I've suspected some of the wire splices related to the throttle body were compromised somehow because I've removed and installed it at least a dozen times, and also the wiring at camshaft sensor B bank 1. As you know there's not a lot of room to get back there to replace the spark plug and coil pack for cylinder 5 without moving the tubing holding the wire harness to the coil packs/sensors.

Here's a recap of what happened, including fault codes (in order from first to most recent). Hopefully it can help someone out there going through the same thing:

1. Engine suddenly almost stalled at stop sign, failed to respond as usual when accelerated, and VSC engine light came on. Was able to drive her home
2. That evening I ran the scanner and it detected a P0355 (Ignition Coil 5 Primary/Secondary Circuit)
3. Since I had to take her all apart anyways, I got new plugs and coil packs and replaced them all.
4. After putting everything back except the windshield wiper motor and the metal tray, I tried starting her but she stalled.

So I rechecked all the vacuum/electrical connections, reset the ECU, and tried starting again but it continued to stall. I scanned and detected these codes:

1. P0029 (Exhaust Valve Control Solenoid Circuit Range/Performance Bank 2)
2. P0102 (Mass or Volume Air Flow Circuit Low Input)
3. P0113 (Intake Air Temperature (IAT) Sensor Circuit High Input Problem)
4. P0121 (Throttle/Pedal Position Sensor/Switch "A" Circuit Range/Performance Problem)
5. P0123 (Throttle Position Sensor (TPS)/Switch A Circuit High Input)
6. P2135 (throttle/pedal position sensor/switch A/B voltage correlation)

I double-checked everything again and after resetting the ECU and again trying to restart multiple times, it was still stalling. But these set of codes all went away. What the scanner detected next was:

1. P0348 (Camshaft Position Sensor A Circuit High Input (Bank 2))
2. P0393 (Camshaft Position Sensor B Circuit High Input (Bank 2))

I double-checked everything again and reset the ECU again, and then tried restarting again. It continued to stall but these codes cleared. That is when I let the car sit overnight, cleared the ECU again in the morning, then ran the OBD scanner again and got:

1. P0368 (Camshaft Position Sensor "B" Circuit High Input (Bank 1)).

I inspected everything again and cleared the ECU and tried restarting, but it still stalled and continues to stall. The major difference is that now after resetting the ECU and running the scanner multiple times, only P0368 is showing up consistently.

Just in case the sensor is in fact bad, I went ahead and ordered one (it may have been what caused the P0355 code to begin with). BTW- if it helps to know all the spark plugs were in need of replacing, and the coil packs very likely were the original ones because they looked pretty worn down externally and were stamped with the old part # (90919-02251) that has been updated a few times now (I bought the car used about 10K miles ago).

I will continue to check the wiring and will install sensor when it arrives, and will post update as soon as possible.

Thank you again for your help. Much respect!

 

UPDATE (3/5/20):
I installed new camshaft sensor at Sensor "B", Bank 1 [part #90919-T5005], cleared ECU, and tried restarting but she continues to do the same thing... turn on for about 2-3 seconds then stalls!

The good news (I suppose) is that OBD scan is no longer detecting any fault codes! I'm going to let her sit over night and try it again in the morning.

One thing I'm noticing now is a real strong smell of gas fumes.

Just to reiterate, all I did was disconnect air box, throttle body, cleaned throttle body, disconnected plenum and vacuum hoses, disconnected coil packs, removed spark plugs, disconnected and removed camshaft sensor B on bank 1, and then reconnected everything back to the way it was. I took my time and was very careful. Short of putting the old spark plugs/ coil packs back in, I've disconnected and reconnected everything, and double checked everything, at least a dozen times now.

When it turns over and is on for a few seconds, it purrs like a kitten and sounds great. But it just won't stay on, and now it there's a strong odor of gas fumes to the point that I have to leave the garage.

Please let me know if anyone has any other ideas.

Thank you!