I dont know if this is the correct spot to post this but I have done some searching and have a weird issue occasionally. My 99 z28 runs great and sometimes whennits warm after a long drive I will shut it off and when I go to get back in it and start it it wants to idle low. About 400-500 rpms. If I drive it and push clutch in it wont die but it idles really low. What do I need to look into for this issue? The car has been tuned by frost and has longtubes, and slp lid. Thats all. Thanks.

 

Can you replicate the issue and check fuel pressure at that time?