1999 Nissan Sentra GXE stalls at start-up

Hi!



I have a '99 Nissan Sentra GXE. When I start the car in the morning (in cool temperatures) the car starts perfectly. But in very hot temperatures, the car stalls and sputters upon start-up. This stalling also happens when we’ve had a huge rainfall and when I shut off the car for a few minutes then try to restart. And this stalling is totally random! Sometimes the car will start numerous time - even when it’s warm! To start it, I have to give it gas just before the car sputters out - then the car stays on and no problems.



Any ideas? I took it to the mechanic and he’s stumped, and the Nissan blogs are confusing (there’s too many suggestions).



Please help!



Thanks!



Christophe Casamassima