Edmunds Answers



  • MrShift@Edmunds 09/07/12 8:27 pm PST

    No codes? Then do a fuel pressure test.

  • dgcart 09/07/12 8:36 pm PST

    i was wonder about convertors. between concertor and resonators it has 4

  • MrShift@Edmunds 09/07/12 8:53 pm PST

    That should throw a code and light up the check engine light, and if it's clogged, it would be blazing hot as well.

    But converters can usually be tested in place pretty easily.

  • dgcart 09/07/12 8:56 pm PST

    what about map sensor? i just dread dropping the tank and being wrong

  • dgcart 09/07/12 8:59 pm PST

    it has about 150,000 miles on it but had aways run good till this

  • MrShift@Edmunds 09/07/12 9:30 pm PST

    No need to drop the tank if you do a fuel pressure test and it comes out okay.

    Sure you could clean the MAF sensor if you use the proper solvent. Or replace it.

  • dgcart 09/07/12 9:34 pm PST

    1 question, if its the fule pump why would it run ok if i bring up the rpm in park and not cut out more

  • MrShift@Edmunds 09/07/12 9:42 pm PST

    Because the engine isn't under load at idle...when an engine does work, it needs much more fuel, so pump has to work harder.

    Mostly I suggested that so that you can eliminate this as a possibility. Very often good diagnosis is about getting to "yes" from all the "no"s.

    I agree though that a catalytic failure would have given more warning.

  • dgcart 09/07/12 9:55 pm PST

    what sjould the pressure be?

  • MrShift@Edmunds 09/08/12 10:38 am PST

    Fuel Pressure 30-65 psi (207-448 kPa)
    Flow Rate 24 lbs/hr

    (for non bi-fuel models)

  • hatwood 09/24/12 7:03 pm PST

    sounds like an o2 sensor

  • zaken1 09/24/12 8:56 pm PST

    On an engine with 150,000 miles on it that starts doing this; the first thing I would do is to run a compression test on all cylinders. If the compression is below 140psi in 2 or more cylinders; the engine will have to be rebuilt in order to run right.

    If the compression is more than 150 in all cylinders; I would replace the intake air temperature sensor. This is a low priced part which can have a huge effect on smoothness and power. If you need another option; I would also replace the ignition coil and the plug wires.


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