after completing an hsr swap i took the car over to kevin91z for a tune. timing was horribly off, fixed now, battery was dead, new battery, fuel pressure maybe at 35, but once car is turned on, the car will not stay on unless you gas it off and on, fuel pressure jumps around 35-37. new fuel filter installed. same issues. when i turn the car on the rpms jump to about 5,000 then drops and leans out. if i gas it i can keep the car on but the rpm jums from maybe 4500-5000 to 2,000 back and forth. im a bit lost maybe iac, or maf, i disconected the maf and same issues, keep in mind parts installed were used and installed im unsure what works and what doesnt besides going on the sellers words that everything worked prior to being pulled


car is an 88 350 maf system, any help is apreciated, by the way the ses light comec on i will retrieve codes tomorrow and work from there.