Will49

Have a weird problem with my 01 RX300. I have had problems starting it on rare occasions. When I turn the ignition, the engine turns over fine, but then dies right away. If I give it some gas it will stay turning over (up over 2000RPM), however as soon as I let off the gas it will die again. After a minute or so at 2000RPM it will be able to stay running without any extra gas.

This has happened to me about 6 times now. One time I had it towed to the dealer and of course it started right away when they tried it (this was when it first happened and I didn't know the "trick").

I have kind of narrowed it down as to when it happens and it seems to be when it is left parked with the front end up on an incline. Doesn't need to be much of an incline 10' or so, and has happened when parked for less than 10 minutes.

Every other time it starts perfectly. When it does misbehave, once it is up and running it is also perfect.

So I'm wondering what may be going on that would cause this? I thought the gas was maybe draining back down the line when on an incline, or maybe a dirty fuel filter, weak fuel pump maybe?......

Any ideas anyone, or anyone who has also experienced this?

ChampGS3

iTrader: (6)

This is nearly the same issue I have with my 02 RX300. Lately I have noticed the intermittent starting issues but in my perfectly flat garage so I honestly think the incline you mention with yours really doesn't have anything to do with the problem we have, perhaps its just coincidental.

Also, I haven't noticed any decline in performance or MPG once up an running. Trying to solve this issue, I replaced the original spark plugs that had ~115k on them with factory spec iridium NGK's, and replaced the pcv valve while I was at it. Within a few weeks I the erratic starting has shown up again.

This issue seems to coincide mostly when I run the gas tank down to very close to "E" and then do a complete fill up at the Racetrac down the street. The very next start seems to be the one that immediately dies, then requires me to give it a little throttle to get it running. Perhaps some moisture in the empty tank, maybe the in-tank filter sucks up this water then dumps it into a section of fuel line upon fill up and when this section hits the injectors we have to throttle past it?

Maybe the throttle body could just use a good scrubbing, which mine has never had. I am running a couple bottles of Lucas fuel system cleaner to see if that helps any. Anyway I will keep you posted on what I find, and let me know what you come up with also.
Thanks.

ChampGS3

iTrader: (6)

I just found it after I typed that long reply.
The search is our friend...here is the exact cause of our problems.

https://www.clublexus.com/forums/rx-f...-write-up.html

This will take all of 20 minutes, Happy Cleaning!

salimshah

Fail to start needs a bit of elaboration.

on start -> does the starter spin
-> does the engine spins and estimate the rate of rotation the same when it does start. Take a guess
-> Does it help to idle if the gas pedal is depressed. [if yes check IACV]


Salim

Lorider680

Sounds like a fuel filter to me, or worse, a fuel pump.
F

Lexmex

That high RPM goes toward an IACV problem (and cleaning). I used to park on inclines in Mexico City and unless I was low on gas, did not have that issue. However, IACV issues (partly because I ran a ram air system) would inevitably lead to a fluctuating idle that would go either very high, very low or just waver around sometimes my RX300 would die at a traffic light. A good fuel injector cleaner could also help, but the IACV should be cleaned out first.

Dadikins

Experienced the same problem this morning with my 2002. Car started fine this morning - drove it around a1/2 mile to get coffee, parked at slight (5-degree or so) decline (nose facing down)

Returned after around 20 minutes. Engine cranked, went to start, then sputtered & died. Tried starting again, same issue. On around the 7fh attempt (with the 3rd & subsequent pushing on the accelerator as it tried to catch), it finally started. Let it idle for around 10 seconds at 2kRPMs, and was fine from that point forward.

No rough idle when stopping, around 500RPM when stopped. Weird.

It almost seemed like the immobilizer wasn't allowing spark after the initial "catch". No CEL, around 1/2 tank of gas.