Looking for some advice/recommendations on my 15 F-sport.

Im the second owner and have had the vehicle since 50k its currently around 140k. Performed regular maintenance and oil changes, never had any issues with the car up until recently.

One morning I had a bit of a rough start which was odd but the car drove fine. A few hours later went back to start the car and it wouldnt turn over. After a few attempts and boosting still no luck . Finally got the car to start with gas pedal pressed to the floor.

Once I got home the problem was persistent. Would only start with gas pedal pressed and the revs would bounce for a bit, car would choke but eventually once driving no issues. I replaced the spark plugs as this started around the manufacturers recommended interval to swap them. The problem was still there but now it wasnt consistent, would happen every other time i start the car. Check engine light came on and each time was pulling different codes:
-P1604
-P0300
-P0102
-P0113
Codes varied from multiple random cylinder misfires to MAF. Re-checked the plugs and cables, didnt find any issues. Now when i start the car in the morning it turns over and starts fine. Leave it to sit for a few hours and go to start again, it turns over for 5-15 seconds and finally starts. No rough idling. I found that on super cold days its not as bad but still there.

Took it to Lexus for diagnostics. First time around they said it was the battery and probably bad gas (I never use less than 91 but mostly 93/94 from petro or esso) to which they recommended to empty the tank, which is a ton of labor. When I mentioned that there was less then half a tank and that didnt make sense for such a labor intensive job they agreed and said its better just to burn out the gas and use 94 only from petro as they are government owned or something like that so they have the cleanest gas as other stations can have water/rust mixed in. Got them to swap the battery, burned through the tank and next few fill ups only used petro 94 along with some fuel treatment and injector cleaners. The problem was still there.

I wasn't too happy with the service so I took the car to another Lexus dealer. They said all the diagnostics look fine, and all they could say was possibly to change the starter or other parts but couldn't guarantee as the tests on the starter and everything else came out good. They returned the vehicle and didn't charge me for the diagnostic.

I tried cleaning the MAF sensor and throttle body but still have the same issue. Looking for some advice or recommendations on a reputable shop in/around Toronto that would able to diagnose whats going on. Thanks for the help!

I've attacked a link to a video of the problem This is on a colder day so the turn over is much quicker than usual

 

Have you checked whether your vin is affected by the fuel pump recall?

 

I haven't received any notices and when searching my vin nothing shows up

 

It sounds like the starter assembly skips a beat as it turns the engine over (but the engine doesn't fire/crank-up), which indicates the problem may be with the crankshaft position sensor.

 

Thats the starter bro

 

Having same problem on my ls460 (2006) 120000K getting more frequent. No error codes. Mine only on cold start. Once a missed start it enters into same cranking scenario that you are having. Steeping on accelerator speeds start. also I have to wait a minute before restart or just cranks like no gas. Once running no issues.
What engine?

 

3.5L

Mine starts perfectly normal on cold start, its once the engine warms up then sits it happens next time I start. When temps are below 0 it starts much quicker as in the video, when warmer it takes longer. Replacing plugs, battery, cleaning MAF and throttle body got rid of having to step on accelerator issue but before that it was consistent on almost every start up would struggle or required stepping on the accelator.

 

Cleaned M.A.F.and throttle plate yesterday Found some contamination on M.A.F back of air flow direction. and carbon on throttle plate and housing.
Start OK then some miss-fire (cough) as cleaning fluid cleared out (no Codes) drove around block all good had engine sit all day in driveway. Start engine OK seems more eager to fire up. time will tell. 4.3 liter engine

 

Its best to let it fully dry before starting, and make sure the cleaner is sensor safe. My car was parked for over a week, now its not having any issues but well see what happens as the weather warms up.

 

I know EXACTLY what your problem is. I've never experienced it on my GS350, but I've dealt with it on another vehicle I used to own.

Fuel Pressure Regulator, it's located on the fuel rail. Its purpose is to ensure the fuel does not drain back to the gas tank so when you go to start it, fuel injects into the cylinders immediately.

When your FPR is bad, the fuel will drain back to the tank after sitting for some time. When you go to start the car, your fuel pump has to pump all the way from the tank to the cylinders.

If you kill the car while it's running, then restart immediate there's no problem right? But if you sit for some time then crank, there's a delay and pumping the gas pedal will help it start faster. If that's the problem, I almost guarantee it's the fuel pressure regulator.

I don't know how hard of a fix it is on a GS350, but on my other vehicle it was as simple as popping the hood, loosing a clamp, disconnecting hose and a couple screws then installing.

 

I have a 2010 lexus ls460 this same problem started around 11/2019 an its still here i cannot figure out what it is also I was going to swap the low pressure pump in the tank an also change the fuel pressure regulator in the tank also located on the fuel pump itself to see it this helps

 

2010 lexus ls460 mine is doing the exact same thing right now it started around 11/2019 and is still doing it now

 

2010 lexus ls460 is doing the same thing right now I dont know what it is it started out the blue around 11/2019 and is currebt now been to the dealership 5 times they can't find the problem

 

Update: Problem has not reoccurred since I cleaned the M.A.F. and the carbon in throttle plate and housing. I have even had instance where engine did not fire (not cranked long enough) When second a tempt which usually went into a crank crank scenario car now fires up just fine.
"Fixed" (Computer logic gets messed up) I have driven without problem since I posted this. 129Klm on car going to be hard to part with this car.