Fuel System Diagnosis and Repair

here is a quick guide on how to check your fuel system. the basic operation of a fuel system is to supply the engine with fuel. if one or more part of the system is not working correctly may or may not run correctly or random stalls or suddenly dies and doesn't start. i have found thru years of working on cars that fuel pumps either die all of a sudden or they slowly die as in our 1996 jeep we had it started out that it wouldn't have any get up and go at high end but it would drive just fine. then it slowly started to get worse as time went on, one day my wife was driving it n it completely refused to go any higher then 1400 rpm without choking out. when i checked it with a fuel pressure tester. it had 15 pounds of pressure. the jeep required 45 psi at idle. here are the basics to check to confirm its working as it should.



1. Does the vehicle start and run? (then you are probably fine but you should check fuel pressure at the injector rail on the engine)
2. Does the fuel pump Prime when you turn the key to on? (if it doesnt prime then you may have a bad pump or blown fuse or bad relay)
3. have you checked all the connections, relays,fuse's?
4. have you changed the fuel filter in the past year?
5. have you checked the fuel pressure yet (there is a valve stem looking thing) hook up the gauge to it make sure its Finger tight. turn the key to the on position and check the pressure if the pressure doesnt build then there is the problem, or if it does build does it hold pressure? does the pressure only go to the low side of what the vehicle calls for use google for this)
6. if the pump isnt turning on and you have verified that the pump is non operational then the next step is to see if you can easily remove the pump or if you have to drop the tank most newer cars there is an access hole in the trunk or under the back seat.
7. obtain a new pump assembly if possible or a good used one major price difference
8. google the directions to change your fuel pump
9. follow number 2,3,4,5
10. you just saved about 500 doing it yourself vs a shop at part plus labor