How To Test The Fuel Injectors (1997-2001 4.0L Ford Explorer And Mercury Mountaineer)

By: Abraham Torres-Arredondo
Created: 12 January 2022
Updated: 17 August 2023
Articl Id: 1100

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Important Precautions When Removing The Intake Manifold Plenum

If need to perform a multimeter resistance test on any of the fuel injectors under the intake manifold's plenum, keep in mind the following two suggestions:

As you're removing bolts, nuts, etc., from the intake plenum, place them in a container and away from the engine compartment.
- The idea is to avoid having anything fall into the open intake manifold runners.
After removing the plenum, cover the open intake runners with clean rags (shop towels). These towels will keep things from falling into the open runners.

If anything falls into the open intake runners, without you knowing, and you start the engine, you're going to be in a big world of hurt!

The only way to remove what fell in, after you've put everything back together is to remove the cylinder head(s). So be alert and be careful.

Don't worry. The plenum can be removed without complications or unhappy endings by simply following some precautions.

One last thing, when you reinstall the plenum, use new gaskets. Install these gaskets without any sealant, like RTV silicone. Using a sealant like RTV silicone may cause vacuum leaks down the road, and you're back to square one (removing the plenum).