Robert LaRose

Hi I have a 99 jeep 4.7 , ive never had a issue wit this vehicle before. I pulled into the drive way shut it off for a minute went to go start it and no start, every thing works when the key is turned to on position, except for the fuel gauge and the volt gauge stopped working. Also I no longer hear the fuel pump pressure up at all no buzz from the pump. it cranks over no problem. I just replaced the CPS sensor behind the starter and it didnt solve the problem. read that one on a jeep forum too. PLEASE HELP!!

jon-d

based on your description sounds like it might be a fuel issue? there is a valve with a black cap located on the fuel rail that you could use to check pressure with. Autozone has a lend-a-tool program so check to see if they have a fuel pressure tool. if they don't then harbor fright has one or you could make your own pressure gauge. check pressure and monitor how long it takes to bleed off once you get it attached.


other things to check are spark, power to your fuel pump (after checking pressure), fuel filter. things like that.

Cherryokee

Did you replace the CPS with an OEM part? Anything else is a crap-shoot. I know it's a PITA to replace but seriously, experience has taught me that aftermarket CPS are unreliable.

dave1123

Welcome to CF!

It sounds like a voltage drop in the main line from the battery to the PDC (Power distribution center. The fuse/relay box under the hood). Check the smaller red wire that comes off the battery clamp for corrosion inside the clamp itself. This wire provides power to everything BESIDES the starter. Because the voltmeter and fuel gauge don't work, I'm thinking low voltage. This will cause all kinds of weird stuff to happen. Believe it or not, all the data displayed on the instruments comes thru the PCM bus and not from the individual sensors.