Sounds like you could have a blockage. The bottom hose runs to the water pump. If you look under the left side of the engine(exhaust/intake manifold side) you'll see where the hose goes onto the water pump. You can always pop it off and take a look. You would be surprised all the crap that builds up after the years. Esp if it's been sitting.

 

I attempted to search but didnt really find something at helped .
My jeep starts in any gear (auto) back up lights sometimes don't work and random down and up shifting when driving at a constant speed.. my search has told me its most likely the NSS but I can't seem to find a DIY on how to adjust it or remove it to clean it any help would be appreciated.

 

http://go.jeep-xj.info/HowtoNSSrebuild.htm

 

Sounds like a coincidence, IIRC the NSS isn't capable of modifying shifting. The TPS however is.

Try this here: https://www.cherokeeforum.com/f2/free-quick-fix-41821/

TPS testing varies slightly based on year. In each case closed should be close to 0V output, sweeping up to anywhere from 3.5 to 5V at wide open depending on year. You can test this with an analog multimeter with the leads stuck into the backside of the TPS's plug. The needle should move smoothly, no jumping. It helps to think of the TPS like a volume ****... Electrically they're the same thing. I prefer an analog meter for this task to visualize it. Many cheap digital meters have significant lag in displaying correct numbers so it's difficult to tell.

Also how is your transmission fluid condition? When was the last change?

 

Thanks Salad for the response. But when you say she is shot are you referring to the actual TPS? Also, what numbers/volts should the harness, while not plugged into anything test. My harness is testing just as high unplugged as when it's plugged into the TPS at zero throttle.

 

ok...i've been looking at possible fixes to this problem on here for the past 2 days...and i still need help.
i have a 2002 Jeep Grand Cherokee.
blower motor works fine...no whistling, no loud noises.
heat and air only comes out of the defrost...nothing on the floor or out of the front panel.
cruise control works fine.
any suggestions on where to start looking for a DIYer?
Thanks!

 

double post

 

not sure about wj but ive read about this issue with xjs where the vacuum line came of the intake manifold causing only the defrost to work, or maybe your mode door is broke...

 

jomps-
thanks for the quick reply...i did notice that the hose from the intake was cracked a little on both ends...but thought it that was the issue that it would affect the cruise too? am i wrong?

 

That's correct. The TPS has 3 connections, one is +5VDC input, one is the potentiometer output, the other is just ground.

 

Hey,
I keep getting this add in my gmail. Does anyone know if there's any truth to it?
$69 Jeep Wrangler Chip60 Horsepower Increase 7 MPG Boost Custom ECU Chip Easy Installation
www.GFChips.com

I suspect it's BS, but if anyone has any personal experience with it, I'd love to hear.... The MPG boos would be great even if it was just 2-3 MPG.

 

$69? fake

 

that was my thought. Just wanted to see if anyone had actually bought it.

 

Idk bought the site that just seems weird. Get some more opinions other than me though

 

yea it's fake. Also you cannot "chip" the PCM in these trucks. It is what it is - as it came from the factory, no way to change it.