Map sensor voltage low

2001 with I6, 130K miles on it. Sorry this is long.

This started about a month ago when the jeep would hesitate and chug when accelerating hard. I got a tune up, ran some fuel injector cleaner through it, cleaned the throttle body. It ran fine for about two weeks.

I started to hesitate again this time at 60+ speeds and not just under acceleration. Well the engine light was on so I took it to autozone and the code reader said map sensor voltage too low.

The guy said that the sensor is probably just old and is clogged. So I got a new sensor and some new tube for the vaccum line and called it a day. We were driving to visit some family the next day for thanksgiving and it ran great, I noticed a little hesitation over bumps every now and then. Then about three hours later it started to chug hard sporadically, even in reverse. Driving home the next day it chugged hard when I went over bumps and sometimes during acceleration.

So I took it back to autozone and the code read the same thing. So I got a new sensor and some smaller diameter tubing. Well driving home it started chuging hard again and the engine light is back on.

Do you all have any suggestions at what else I could look at for this problem? The wires have a good connection to the sensor as does the vaccum line. And I find it hard to believe its the sensor since Ive tried two new ones.

Any ideas? Thanks!

I ran into a similar problem and found I had issues with other vacuum lines as well as an EGR solenoid. You may want to take a close look at all of your vacuum lines.

I replaced the vacuum line. I'll look into the EGR solenoid

Low map voltage, if the sensors good means your vacuum is low. The MAP sensor reads the manafold vacuum.

langer1 said:

Low map voltage, if the sensors good means your vacuum is low. The MAP sensor reads the manafold vacuum.

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Any ideas on what would cause the manifold pressure to be low and how to fix it?

The vacuum line is brand new.

Ryan4x4XJ said:

Any ideas on what would cause the manifold pressure to be low and how to fix it?

The vacuum line is brand new.

Click to expand...

There lots of vacuum lines, any one will cause a low reading.

Un-hook and cap all the vacuum lines accept the MAP sensor and connect a vacuum gage.

If the readings normal 17hg then reconnect the lines one at a time until you find the bad one.

It it's not normal will the lines off and capped then it valves, timing or a bad gasket.