02 Rx300 sporadic Idle issue

[Jay29]

2002 Lex RX300 awd ... This has only happened once before and it was like a year and a half ago in the middle of winter. It just happened to me again in hot summer weather. 

After doing some light general driving around. (No AC on or hard acceleration) I pull into a parking spot and shut my car off as usual. About 8 minutes later I get back in, start my car up... it initially starts up normal and then the RPMs fall right down and it cuts out. (No bobbling.. just 1,000 to 0 a split second after ignition) So I restart again.. same thing happens. If I gently push my gas pedal down a little bit, it starts up and stays running, but as soon as I take my foot off the gas the RPMs drop right down to zero and it cuts out again. I'm able to drive home, which is literally a minute away by keeping my right foot slightly pressing down the gas pedal so it stays idling and then use my left foot to brake. Lol Oddly enough, when I got home from my short drive home, I pull into my parking spot and the RPMs stay up at idle without having to press the gas pedal down a little bit. (Apparently my truck can fix itself)

Anyone have any clue what's going on here? I've had my mechanic look at it, but because it's not something I can replicate or it doesn't happen often enough to notice anything about my driving pattern, we're both at a loss to figure this one out.

Someone suggested a faulty PCV valve?
As a footnote, with the exception of these two instances, it idles perfectly all the time and is pretty well maintained.

 

Just for reference, this never happens if the car starts up properly.. i.e. while driving it will not suddenly drop to zero if my foot is not on the gas after a proper startup and idle. This only ever happens if I experienced this glitch while starting. Even if I'm driving down the road while experiencing this, the second I take my foot off the gas pedal RPMs drop to zero and stalls. (2000 rpm to 0 while in gear driving) I have on several occasions tried to reset my ignition by pulling the key completely and it still happens. Then spontaneously it won't happen. 🤔 

 

Pretty weird, right?
 

[RX400h]

Perhaps this may help?

 

[Jay29]

This is exactly what's going on. You're a lifesaver bud! At least I know it's a pretty easy fix and something I can do next time I zip up to the lake. Thank you again!!