jonb8

4.0, auto, renix fuel injection. When I start the jeep and drive about 3 miles everything is fine, then it will start missing real bad and the fuel pump is loud. When it started missing I pulled off the air box lid and it sounds like its coughing. Anyone have any idea's? Thanks.

jeeptech

Fuel pump is a good place to start, check pump pressure 1st. It should be near 40 psi and pump solid fluid.

drakan1908

Jonb8 there is a guy on this site http://www.teamtrailblazer.com/ named xjtrailrider that knows a lot about the renix systems. I will try to get him to get in touch with you or just join ttb and ask him your self. This is a local group around the roanoke area.

BlueXJ

The renix fuel injection fuel pump has a relay on the passenger side fender well (one of three) and it could be a little burnt. I switch mine for new ones once a year and keep the old ones for spares. They are about $4 each at Advance AP store IIRC. Try that and see if it helps. If not then PM me and I will link you to an excellent Renix site. RENIX RULES ! ! ! !