03 Explorer--starting trouble.

i have the same problem as he does??? i have a 2003 explorer 4.0l sohc and i was driving and it just lost all its engine power and with the gas peddle to the floor it would go to 2k rpms and then it just died when i start it it will generally get an idle of 2k then 500 then 2k then off it will not stay running even with the gas peddle floored. im at a loss i have fuel pressure i just changed my plugs and idk where to go next i have asked around and still not sure i also ordered iac valve should be here today to try that!! any help would be greatly appreciated!!

Welcome to the forum!

Did the idle concern start before or after you changed the spark plugs? Have you inspected the few vacuum lines that are under the hood to make sure they are in good condition? Do you have a check engine light illuminated? Even if not, you might want to have the system checked for pending codes. Many of the chain auto parts stores will scan for codes at no charge.

Also, in the even you checked the air filter just before this issue started, make sure the MAF sensor is plugged in and that all the intake air tubing is properly attached.

-Rod

my check engine light is not on and i replaced the plugs after the event and i can hear a loud hissing noise im just not so sure how to find my leak?? will a vaccum leak stop my vehicle from starting??

Yes, a big enough vacuum leak will cause a lot of driveability issues. There should be a vacuum diagram under the hood showing the main vacuum lines. Also, don't forget to check things like the intake air tubing and the Mass Air Flow (MAF) sensor connector. Some of the older Explorers had issues with intake manifold gaskets, but I don't recall reading of too many 2003 range Explorers with that issue.

-Rod