93 Jimmy stalls out after getting warm

[mattw4kids]

Here is the deal... I have a 93 Jimmy, and it stalls out after I sit in slow moving traffic. No problems on freeway driving, and this only happens after it has warmed up. When I go to restart, it crankes up fine, runs for 20 seconds, I hear the fule pump whine, then it dies=- like its running rich. After it dies, I hear the fule pump whine for another four seconds or so. After it sits for about 30 mins, It runs fine.

It has been to the shop a few times for a fule pump replacemet, a fule sensor indicator, and then for the third time a thermostate and a temperature sensor replacement. The mechanic thought that it was running rich due to the temp. sensor being bad. The mechanic has found nothing wrong on the computer tests, and Im loosing my mind. Any suggestions? Or should I just drive on the freeway and not get stuck in traffic- where I am a slow idle/RPM....

[BlazerLT]

check the fuel injector and internal fuel line kit for leaks.

Leaks will be seen as washing in the upper plenum.