I have a 91 Ranger, 3 liter. I have been having a problem with a rough idle. I checked the web and noted that it could be caused by a MAF sensor problem. What is strange is that I have both a MAF sensor and a MAP sensor. At least I think I do. The MAP sensor is located on the passenger side firewall. It doesn't have a vacuum line running to it. The port on the MAP that the vacuum line would attach to, has a round grey piece of plastic on it. This prevent a vacuum line from being attached. The MAF sensor is in-line between the air-cleaner box and the throttle. So I have two questions:
- Why would the engine have both a MAF and MAP sensor?
- Should the MAP sensor have a vacuum hose attached to it?
Thanks!