97 cherokee sport 4.0. 214,xxx miles

started with the temp gauge never getting higher than 160 degrees. eventually is started getting harder and harder to start. after that, it would only start after it had been sitting for a couple hours and once it ran for a little bit, you could only start it by giving it gas but it would stall if you took your foot off the throttle. likewise, if it was cold and started fine, once it ran for a couple minutes, it would stall if you took your foot off the gas. I unplugged the sensor on the thermostat housing and it stays running now but the electric fan kicks on right at start up and i get horrible gas mileage for obvious reasons. I searched this and everyone seems to have the first problem but i didn't find anyone with the stall condition. thoughts???

 

1. The target coolant temperature for the 4.0 is 200-210. You need to get there. You may have a faulty thermostat or a reading that isn't real from the sending unit. Start by pointing an infrared point and shoot thermometer at the coolant housing. Then you'll know if what you are seeing on the dash is real.

2. Stalling is a common symptom of a marginal battery. Have your battery LOAD TESTED. Any parts store will do this for you for free.

3. Fresh tuneup parts whenever chasing driveability symptoms. Champion copper plugs gapped to .035, new plug wires, distributor cap and rotor

4. Still happening AFTER all of the above is addressed? Test your "throttle position sensor". And clean the throttle body and idle air control. They get carboned up over time and miles.

 

thanks for the quick response. I will let you know if that fixes it.

 

x2 on what tj said. Mine turned out to be a really dirty throttle body/IAC and a marginal battery. I had the exact same issue, i mean exactly what you said. I just cant make short trips more than once or twice in a row, but still using the old battery. Temp still runs low, but not effecting my mpg since I ran some injector cleaner through and its making up for the difference.