okay..well i had a guy work on my 91 formula 5.7 and he took it apart and then ran off with all the cash and never came back..he took the whole intake off the engine (tpi)..so i got the car back and put everything back together with what needed to be changed (fuel injectors, egr valve, intake gaskets) and the car will crank but it doesnt stay running. It will crank up the first few times and shut right off..idles up high and then shuts off immediately. then after a few times of that i can give it gas and make it stay running..it will try and idle down and die but sometimes it will get through taht and idle back up..it backfires also every now and then but my cats were cut off maybe tahts why idk?? i messed with the timimng and nothing changes..i made sure the whole intake from the block to the runners was tight. im thinkiing maybe one of teh vacuum hoses are connected wrong??? i dont know where everything went so i kind of just placed it where it seems to fit. some help would be nice because i am trying to sell the car..thanks alot TFS

Hello,

I think you already nailed it, check for vacuum leaks. '91 should be a speed density system and is exceptionally sensitive to vacuum leaks. I hope you can solve your car's problem. God bless.

-Chvrlt283

the problem is that i have done this before (taken apart and put back together the whole TPI system and vacuum) but i dont remember where all the vacuum lines are suppose to go lol some look like they can go someplaces but they may go to another place at the same time. i need a detailed vacuum diagram or something. once the car is running its a little hard to keep it running. it keeps dying out. and i dont have a trottle bracket thanks to the douche that took everything apart, so right when u crank it i have ro run under the hood and hold the throttle open, real pain in the butt.