I have a 1990 YJ with the 2.5L 4 banger that starts very easily and will fast idle for about 10-15 seconds and then it will slowly slow down and die. I then re-start it and it will do the same thing but a little quicker this time. If I hold my foot on the gas and hold it up to about 1500 rpm it will surge about 300 rpm. If I sit there and let it warm up for about 3 minutes it will speed up the rpm a little and then it will stay running and run perfect from then on.
I just bought this without a transmission, so I didn't have a chance to check out the motor, it had been sitting for 1-1 1/2 years, and I was assured by the previoius owner that it ran great when it was parked.
It was doing this even after warm up until I replaced the MAP sensor and now it's only when I first start it up. I have also replaced the fuel filter, and put a new intake/exhaust gasket on since it was leaking exhaust pretty badly.
Any ideas what could be causing this?