2000 Toyota Avalon Engine problem

Any ideas for a very intermittant problem on starting the engine. Twice in the last month on starting, within a second the engine will stop. Doesn’t run so no diagnostic shows. I found I could get the engine to run by holding the accelerator down. The engine will stop immediately on lifting my foot. Finally the problem cleared but w/o showing any lamp. I don’t want to leave w. a mechanic because it could go weeks and not return. Any experience w. this pblm??

Sounds like a problem with the Idle Air Valve, or the circuitry involved with that valve. Sometimes removing and cleaning helps. This is what it looks like.
http://www.autopartswarehouse.com/search/?D=toyota+idle+control+valve&Ntt=toyota+idle+control+valve&Dx=mode+matchallpartial&Ntk=Main&Ntx=mode+matchallpartial&N=4294967025+11797&Nty=1

A code can be set even if the Check Engine Light is not on or the engine is not running. AutoZone, Advance Auto, Checkers/Schucks/Kragen auto parts, etc. will pull codes for you free.