Ok i have 1991 3.1 Lumina with 114,000 mile on it ..on time awhile back my car would die when i shut it off and not start for a couple days...it doesn't do that anymore but after that i started it and it runs rough real rough i hae no rpm gauge to tell you what that was but it runs ruff and smells like its running rich...but not sure put i can put it in gear and try to go some where it will try to die out if i try to floor it and if i baby it it will only go about 20 to 30 miles an hour... it will stall in nutral as well i have been taking it to mechanics and they have no idea...i have replace the coil pack and egr valve i think...thats what that was...tuned it up no to long ago so i have no clue what is going on but if i let it sit for a couple days it runs Fine...perfect almost...then it dies when i get it some where and does the rough idle and stuff agian...plz help i have put too much monety in this car to junk it...new fuel rail also i forgot about that....
and i ahave good fuel pressure...plz help! oh and a used computer out of a 92 3.1 4 door but that was a couple months ago...