Engine trouble

Any help. I have a03 Jeep Grand Cherokee with 4.0 straight 6 . we've changed Crank sensor 4 time's cam sensor . Tps sensor mass air sensor. All grounds were correct ohm's all power points read 5volts fuel pressure reads 60lb running 55 off Still runs rough hard start still throws no crank code. Any ideas

 

If you are not using a oem type cps, I would suggest changing out to one. For starters anyway. To make sure your computer has a good ground, run a wire from the computer housing to the battery negative.

 

I've joined a new underground membership that states a good ground is equally important as a good positive.

 

We have checked all ground's cleaned them put back.check ohm's resistance all are within range .I have thought about putting a ground from battery to comp. What about dirty fly wheel.

 

A lot of starts can have an effect on a flywheel, metal chips can collect on the cps magnet and cause problems. There is a kit that routes the cps to the front vibration dampner. You did say that it has been replaced so it should be clean. I had a bad cps on a 4.0 Grand once and it did not throw a code either, I have heard similar stories. A bad cps will cause a 4.0 to stall and eventually not be able to restart.

 

Yes but we've replaced that sensor 4times now.