Hi there, I have an '87 F150, 4x4, 5.0L. It surges when it idles(only when warm) so I put a code reader on it and it came up with "MAP Sensor Out of range". In my Haynes manual it says I can test it with a Volt meter, I did that and it showed 0 volts.

Anyone else had this problem before? Does it mean that my MAP sensor needs to be replaced or that I have a Vacuum leak somewhere? Just checking on this because I've read alot about this "surging" problem and I was thinking my problem is more then just a quick sensor replace.

Thanks for any help!

 

I had almost the same problem with my '91. Mine would surge all the time, so bad it would stall out when in park or N. Try unplugging the MAP sensor. When I did it idled right down , then I just replaced the sensor.

 

The reason it probably did that backhoejoe is because the computer has a memory of the last....40...or so drive cycles and when you unplug the sensor it will sort of say to itself....these signals are unusual based on my last 40 cycles so something is wrong and it disregards that input and replaces it with memory input....

I don't think you can just check the voltages...I think you need to measure hertz of the sensor's output per vacuum. I've never tried to test a MAP sensor...

 

Well, I think I'll unplug it and get one out of wreck this weekend and give it a shot. Its nice to know that others have experienced the same problems and have solved it. It's really eating my gas mileage (12 MPG)... it's also gutless on the bottom end.