Question about 2003 Ford E250

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I keep getting a check engine soon light. I have replaced all the plugs and wires, the coil pack, both upper 02 sensors and the IAVC motor and the engine still hesitates runs a little rough and the light continues to come on, what do i look for now?

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I was wondering if you scanned this vehicle or guessed on which parts to replace? You can get a free scan at Autozone or Oreillys. Even if you have an basic scanner, there are some scanners that Autozone and repair shops use which list ALL the potential problems starting with the most likely.

There should be a MAF sensor on the Air intake bonnet. It can be cleaned with Electrical spray, but not a solvent liike Choke or Brake cleaner. If that does not help try misting the gaskets on the Intake manifold and Airhorn with a water spray bottle. Do this with the engine running or even use Choke cleaner. Either way, the RPM will change if you find a leak. Since your "Check Light" is on anyway, it would not hurt to plug the Vacuum line to the EGR valve and see if the hesitation stops when you accelerate.

Then check the EGR for a bad diaphram if the motor runs better without it. The scan at Autozone should show the mechanical defects, but it will not show bad gas. You might as well change the fuel filter and do a gas sample at the same time. A lot of people have put a ton of money into their vehicles only to find they didn't need to.

It won't cost you much to try what I suggested, and I think you have already replaced the most popular parts. Would be curious to know what you found out about your vehicle.

Posted on Nov 06, 2010

  • jimairpro Nov 06, 2010

    Yes we did a scan and it came up with several issues, 02 sensor, miss fire on 4, vacuum leak. We tested the intake manifold and could not get the RPM'S to change. As far as bad gas i have filled the tank at least four times since these issues have started so i don't think that is it. I will try the suggestions and let you know how they work. Would the lower 02 sensor have any affect like this? I heard if you replace the uppers you should also replace the lowers.

  • fordexpert Nov 07, 2010

    With this new (to me) info about the missfire on number 4 it may take a bit of driving to cleanse the Catalytic converter for that bank. Also you could start with the lower O2 for that bank as it still may be fouled.

    When #4 plug was removed did it show signs of raw gas? Maybe good idea to pull the new #4 plug and look at it. The #4 Injector may be dirty and the reason the original plug fouled out.



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