K2500 MAP Sensor

I was home way early yesterday because William threw up at school, but after I picked him up he seemed perfectly fine. I was going to need to drive the pickup today because Mary needed to go to Santa Fe all day. I had bought a $15 MAP sensor on Amazon, but the people sent me the wrong part (a Subaru knock sensor).

So we got home and I ran through a test procedure for the existing MAP sensor. You disconnect its vacuum hose and connect a multimeter between its sensor wire and battery negative. With the key on, the MAP sensor should output about 4.7 vdc with no vacuum, and as you apply vacuum, the voltage should drop. Well, it didn’t, so that confirmed a bad MAP sensor.

I bought a replacement one at AutoZone for $50 (with a $20 discount because my loyalty card had accumulated enough points) and installed it.

Wow, that made the truck run better. No more stalling in reverse or when coming to a stop, and idle is predictable and steady. Shifting is improved as well.

… then, after I had driven the truck around the neighborhood and shut it off for several hours, it started leaking coolant on the driveway. The lower radiator hose has a leak.

So I didn’t get to drive the truck this morning after all. Mary took William to school in the Tahoe and drove to Santa Fe. I rode the Goldwing and will ride it down to William’s school at about 5:30, walk him over to Flying Star, and hang out for a while. Or maybe the library.


So I need to get a couple of radiator hoses. Now’s not a good time, money-wise, though.


The people from whom I bought the MAP sensor on Amazon are unwilling to ship me the correct part until they’ve confirmed I’ve shipped back their knock sensor. They’re dicking me around over a $13 part. Good move, guys. I advised them that I will be much more likely to give them a favorable review if they cross-ship, as their delay caused me problems.