I have a 1990 YJ with 2.5 and TBI. IT has been rebuilt 2 years ago and has been my daily driver. Lately it has developed hard to start. I have changed fuel pump. fuel pump relays, fuel filter is new. coil and ignition module. and all engine sensors at rebuild. I have checked all grounds and connections. It also has developed a stumble when the throttle is held steady ant 50 MPH.