vaccuum leak maybe is it running off carb. i have an 89 also but its tbi and has all emissions. let it run with the radiator cap off idk. is the oil creamy. mines dies out to but its cuz it was running out of gas my meater dont work only way it dies when its on low

 

WTF! Is this in english?

 

mine is tbi also. decided to go ahead and build a 350 for it and ditch the 305 for now, may work on the 305 later on but im also in the process of building a 351 for a 69 mustang resto I started on last winter. The guy I took it to said the compression was a bit low and thinks there is a crack in the head gasket and the pistons are building pressure in the coolant. then he said it could even be a cracked head. I picked up a wore out 350 that still runs for $250 so im debating on putting the 350 in as is and working on the 305 to swap out so i can work on the 350. sounds like alot of swapping but my wife likes to drive the camaro and I've been looking at this mustang all winter and need to get it goin. Thanks for all the info thus far. hopefully Ill get the "new" engine in with minimal issues...................

 

yea cant you read