hey guys ive noticed that my jeep has been running rich and i kinda narrowed it down. its got a complete tune up fuel filter and all, o2 sensor, thermostat. Its running at 150 deg when its liek 90 outside. i did some reading and it says that my cts (coolant temp senor) could be the cause. keep in mind theres no codes. its been like this since i bought it

 

What motor is in it? If it's a 4.0L it should be closer to 200.

 

ya its the 4.0

 

I believe there are two temp sensors, one for gauge, other for pcm. Are you sure the thermostat you got is the right one? Rad cap good? Fans running when they should and not all the time?

 

I have one fan and that's the fan clutch for the engine. Yes the thermostat is the right one. And I believe that there is one temp sensor for the gauge and pcm but I culd be wrong

 

If it's the 95 Grand then it has 1 sensor on the t-stat housing for the comp and 1 sending unit on top of the head near the back on the DS that runs the temp guage.I have my electric fan hooked to a switch and if I leave it on too long it will over cool like your saying.Check to see that the electric fan isn't running all the time.If it is then thats the problem.You have a clutch fan and an electric fan .

 

My grand only has the clutch fan no electric.

 

Your thermostat may be stuck open. There is two sensors, one at the back of the head for the gauge and one on the t-stat housing for the PCM.

 

My thermostat was just changed. I see one sensor on my tstat housing. I don't see the other one on the head.

 

You could of got a fualty t stat, or it could be backwards. What temp of t stat did you get? It should be stamped on it some where.

 

192 deg. I replaced the tstat because of this problem and it didn't fix it. U can tell when the tstat opens and closes. Like I said in the first post I'm running rich and this is what I narrowed it down to. For sme reason the comp thinks its still cold. And I replaced the o2 sensor. And there are no codes.

 

Grab the upper hose when warm is it hot? Roughly 140 deg is hot to the touch. Will it over heat is you sit in traffic? will it actually warm up sitting in traffic? Could be a heater core. could be bad wireing for the pcm, or the cooling system needs an acid ran through it.

 

Never gauge never reads hotter than 160deg. The hose gets hot yes. Coolants clean. I'd say its about a little bit more than a quarter away from 210.

 

The sender for the gauge is at the rear between the valve cover and intake manifold, it is not as big as the PCM temp sensor.

 

Would that affect me running rich?