I've tried 2 different MAP sensors and 2 different stock "hard line" assemblies, still getting a vacuum leak when I shake the line, Jeep will stumble and even stall out if I grab the hard line and wiggle it. Both hardlines hold pressure when I blow in it with my finger on the other end, and both MAP sensors are "sealed" when I try to blow into the vacuum port.

Is there a reason for such a small diameter hardline, instead of using 100% rubber flex line between MAP sensor and intake port...metered flow or something?

 

I got a short length of metal brake line, cut off the flared ends, and replaced my plastic vacuum line with it. Not had a problem out of that line to the MAP sensor since.

 

I have been fighting a surge...sputter...stutter....runs fine...repeat issue for a while. I unplugged the MAP sensor and it seems to be running fine now? Maybe I should go back and check the lines to it as well, thanks guys!

 

New or used hard line assemblies? Is the "boot pushed in flush at the throttle body?

 

Why yr do you have, can't tell on app. When I replaced my MAP sensor on my 01 I broke that line. I used reg rubber tubing from NAPA and replaced it. Not a problem since

 

used hard lines. The boots are pushed on as far as I can, it seems like the sensor side is the culprit. FWIW, my engine is a 95, no port on the TB, vacuum comes from the intake. My XJ is a 1990, Autozone shows the same p/n for both 1990 & 1995.
I replaced with standard vacuum hose, seems alright.

grizzly...def. check the vacuum line. When I unplug the vacuum line it almost stalls, usually it catches itself and idles, but really rich, pumps out a gas haze of exhaust.