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Drew, Super Mazda Tech.
Category: Mazda
Satisfied Customers: 2518
Experience:  19 yrs. experience. Mazda Senior Certified Tech, with Ford, Linc. & Merc. experience. ASE L1 Advanced Certified Master Tech.
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Mazda tribute: misfiring..changed coils and plugs fuel pressure

Customer Question

hello there my 04 mazda tribute started misfiring slightly couple days ago and today it starts and shuts off changed coils and plugs fuel pressure is good no codes any suggestions. need help fast as i have someone wating to buy it.thanks for any help u can provide.
Submitted: 5 years ago.
Category: Mazda
Expert:  Drew replied 5 years ago.

Welcome to Just Answer. My name is XXXXX XXXXX I will be glad to assist you.


Did you replace all 6 ignition coils??


Did you replace the intake gaskets??


Inspect the PCV valve and hose for vacuum leak??


Inspect and clean IAC (idle air control valve)


Does it still have a misfire??


After it stalls, will it start right away??


Let me know your results.






Customer: replied 5 years ago.
tryied everything u suggested. replaced two vacum hoses which were broken. and i tried a fuel pump today it starts right up and doesnt misfire but wont stay running. but spray some primer in through trottle body intake and it will run all day .it has new spark plugs. fuel filtre. fuel pump.coils.and still wont run. im at a loss. only thing i havent tried yet is the main computer.dont have one. thats next. i need this thing running has i have a buyer for it.any help greatly appreciated.and oh yes i even cleaned out the converter on the exuast it was plugged to.thanks
Expert:  Drew replied 5 years ago.

Make sure you have also replaced the fuel filter. If it runs on alternative fuel supply, you either have a lack of fuel flow or the injectors are shutting down.


You will need to there injectors of pulse by using a noid light. Connected to each injector, this flashing noid light will tell you if the computer is opening the injectors.


Your vehicle has 3 cat. conv. Both exhaust manifolds are cat. conv. also. You can remove the front O2 sensor in each manifold and start the vehicle. If it runs, that will tell you the front cats are plugged.


Please let me know if you have any additional questions.



Drew and 2 other Mazda Specialists are ready to help you
Customer: replied 5 years ago.
does this machine have a fuel regulater would that do it and how do i check it. thanks
Expert:  Drew replied 5 years ago.

Thanks for the accept. Since your fuel pressure is within spec, I would suspect the rerulator is fine.




The fuel system consists of the following

  1. Fuel Rail
  2. Fuel Injector
  3. Fuel Pump Module (FPM)
  4. Fuel Tank
  5. Fuel Lines
  6. Fuel Filter

The engines are equipped with sequential multiport fuel injection that is supplied by a new returnless fuel delivery system (RFS). The powertrain control module (PCM) is able to maintain constant fuel pressure by varying fuel pump module (FPM) output. This is accomplished by increasing or decreasing voltage supplied to the tank mounted FPM. The RFS offers improved economy, lower fuel temperature and decreased fuel vapor in the tank.




The fuel rail pulse damper located on the fuel rail reduces fuel system noise caused by the pulsing of the fuel injectors. The vacuum port located on the damper is connected to manifold vacuum to avoid fuel spillage in the event the pulse damper diaphragm were to rupture. (The pulse damper should not be confused with a fuel pressure regulator, it does not regulate fuel rail pressure



  1. Remove the throttle body.



  1. Remove the fuel pulse damper.
1Disconnect the vacuum hose.
2Remove the snap ring.
3Remove the damper.



  1. Remove and discard the O-ring seal.


  1. CAUTION: Use an O-ring seal that is made of special fuel resistant material. Use of an ordinary O-ring seal can cause the fuel system to leak. Do not reuse the O-ring seal.

NOTE: Lubricate the O-ring seal with clean engine oil.

To install, reverse the removal procedure.