So I know it has been hot where I live (108* according to news) but the other day my jeeps ambient temp said 120* while sitting in the sun and dropped to 116* in the shade. My question is does anyone know where the ambient temp thermostat is on a 1990 xj and if it is possible to move it where would be the best place?

I've got more questions I just don't remember them at the moment.

Post 11, Exhaust mani: answered (thanks cruiser)
Post 22, Rear window modification Q:
Post 23, Overhead console Q:

Thank you all for at least looking.

 

Remembered another one, anybody know what years have a compatible fuel pump assembly as my 90 xj. I need a new (or new to me) fuel sender so that my gas gauge might actually work.

 

I believe 87-90 for the tank level sensor. Cherokee or Commanche are the same. Later years are reversed, ie: full tank will read empty, empty tank will read full.

I have no idea where the temp sensor is on the XJ.... quite a few cars have them located somewhere just behind the front bumper, away from engine heat.

 

think your right radi. Only problem with this location is it picks road heat up, thats y it is showing more the actual temp. Little black thing mounted below or in front bumper, with one wire going to it.

Cant tell you bout fuel pump

 

[QUOTE=Radi;1964385]I believe 87-90 for the tank level sensor. Cherokee or Commanche are the same. Later years are reversed, ie: full tank will read empty, empty tank will read full.

IIRC, Comanche in 87 to 90 works bassackwards from the Cherokee.

 

Generally you wont get an accurate reading on the ambient temp unless you are moving. Even modern cars will read higher then expected when just sitting.

 

+1
I know the Chrysler minivans freeze the temp display, showing the last stored reading until you've been moving for a while. Makes for some interesting results for a few minutes, lol.

 

Is it possible that if you don't have the correct 50/50, or close, mix of rad fluid and water that the elec. fan won't turn on?

One of my problems I was having when my jeep was getting hot was that the elec. fan wasn't coming on at any temp. I had it as mostly water with a little anti-freeze. Now that I have, at least closer to, a 50/50 mix my fan kicks on just under the 210* mark.

 

Shouldn't have an effect.

 

I didn't think so, I love it when my jeep fixes its self

 

So I have convinced my wife that come tax season I need a new exhaust manifold (and everything else in the system) to improve my mpg, cracked manifold and all.

What I will get is 2.5" mandrel tubing from an exhaust shop and a flow master super 44 with some flex pipe near the manifold to prevent future cracking, I wanted to get the APN manifold but it's only for 91 and up I know it CAN be done for earlier models like mine (90') but how difficult is it, or is there any other comparable manifold for a 90' 4.0.

Finally should I stick with the old cat or get another and which should I get, all help is appreciated thank you.

 

Yeah my other car (which i never drive anymore except when ive blown something up on the Jeep!) is a Saab 9-5 and its outside temp gauge does the same thing. over 20mph or so for a few min and it levels out to the same as what all the bank sign thermometers say.

 

Anybody with info on my exhaust question?

 

Mud Frog sells a great cat back system in the vendor section..... Plus it's reasonably priced too. He also sells cats cheap.
I got a Flowmaster super 44 muffler Magnaflow cat and a 2.5' tail pipe for under $180 with shipping. Check him out.

 

For the header? I've done it twice now. Have a bung welded into the header for the EGR tube. Have a new headpipe made from the header to the rest of the exhaust system and have an O2 sensor bung welded into that.