In this article, I'm gonna' show you a simple but very accurate way of testing the manifold absolute pressure (MAP) sensor on your 4.9L, 5.0L, or 5.8L Ford car (pick up, van).
As you may already be aware, the Ford MAP sensor does not produce a MAP signal that can be measured in Volts DC. You'll need a multimeter that can read Hertz frequency. Yeah, I know, this really sucks if you don't have one but this is the only way to bench test the Ford MAP sensor (if you need to buy one, check out my recommendation by clicking here: Hertz enabled Multimeter -at: easyautodiagnostics.com).
One more thing, this test involves using a vacuum pump, that you can rent at your local auto parts store (AutoZone, O'reilly)... or you can use the ‘good ole lungs’, but I'll leave this up to you.
To help you navigate this article a little easier, here are its contents at a quick glance:
You can find this tutorial in Spanish here: Cómo Probar el Sensor MAP de Ford (4.9L, 5.0L, 5.8L) (at: autotecnico-online.com).
When the manifold absolute pressure (MAP) sensor goes BAD, you'll get a failed MAP sensor diagnostic trouble code.
The manifold absolute pressure (MAP) sensor is one of the most critical sensors the PCM (Powertrain Control Module = Fuel Injection Computer) needs to give the engine in your car, pickup, van or SUV running optimally and so, when the MAP sensor fails... you'll get some hard symptoms.
The fuel system in your Ford vehicle is a ‘Speed Density’ type. In lay man's terms, this means two things:
The PCM then uses both these inputs to calculate the correct amount of fuel the engine needs to run at its best.
Here are some more specifics when you turn the key and start the engine:
The absolute best way to test the MAP sensor is to bench test it, and this is how I'm gonna' show you how to test it in this article. Let's turn the page and get testing...
“For instance, on the planet Earth, man had always assumed that he was more
intelligent than dolphins because he had achieved so much —the wheel,
New York, wars and so on —whilst all the dolphins had ever done was
muck about in the water having a good time. But conversely,
the dolphins had always believed that they were far more
intelligent than man —for precisely the same reasons!”
The Hitchhiker's Guide to the Galaxy