map sensor failure symptoms

1991 Blazer has bad fuel economy, Idles good, but when to acceleration it has a real bad hesitation. I have to feather the accelerator to pick up speed. Could this be the MAP Sensor

Thanks

1991 Blazer has bad fuel economy, Idles good, but when to acceleration it has a real bad hesitation. I have to feather the accelerator to pick up speed. Could this be the MAP Sensor

Thanks
Could be or could be other sensors and or other stuff.
What is the map sensor reading at key on engine off and engine running.?
Always check for good vacumn to map sensor.

Any check engine ligts or codes?

that a V6 or V8? which engine specifically?

i had an 88 suburban with a 350 that had the same symptoms. cyl #1 plug was so fouled that it wouldn't fire. replaced em all and the problem was fixed. Any piston clang or stumbling when you try to punch the accelerator?

1991 Blazer has bad fuel economy, Idles good, but when to acceleration it has a real bad hesitation. I have to feather the accelerator to pick up speed. Could this be the MAP Sensor

Thanks


Not sure if it pertains to your Blazer or not, but my 93 had terrible fuel economy and once I pulled the plenim off, I saw why. The fuel hoses in there leak pretty generously. Pull the oil dipstick. Does it smell like gas? Is the oil level higher? I'd check these because it is a common problem with our Blazers.

The symptoms of a bad MAP sensor is the same as a Massive Air Flow (MAF) sensor.
A bad MAP sensor, would give a bad signal for the air/fuel mix!
deliverability issues, fuel economy, and slow to react to the throttle position sensor.

You can test the MAP with a voltmeter and vacuum pump/gauge. Backprobe the electrical connector for the MAP and turn on the ignition. Connect the vacuum pump and monitor the voltage as the vacuum changes. It should be something close to this:

http://www.wwdsltd.com/files/MAPTable.gif