Temperature, heater, and stalling problems

[kyle.hand]

I have a 98 ram 1500 with the 3.9L V6 with a standard tranny. I'm having quite a few problems that have all emerged at once. I'm hoping all of them are related and easily fixed, but I need y'alls help in deciding where to start.

My first problem began around Christmas. When I come to a stop or go from accelerating to coasting my truck stalls out. It doesn't do it every time and some days it is worse than others. Sometimes it sputters but it usually dies with out much warning and many times the only way I know it is from the power steering not working. It has no trouble starting back up.

The second problem is related to the Temp gauge on the gauge panel. The gauge never gets above ~ 150. My third problem is the heater doesn't HOT air. It will blow lukewarm air but not hot air. This honestly isn't a problem as I live in Texas but It sounds like something that could be an indicator of the problems above.

So this is what I have already replaced:
Crankshaft Position Sensor ~2 years ago during a clutch rebuild
Thermostat ~1 year ago while replacing a short hose that runs from the block to the water pump
Engine Coolant Temperature Sensor 2 days ago to see if it would help with these problems

I'm lost and not sure if any of these are related or if they're all independent of one another. What says the forum?

 

[Bigtman07]

Sounds like you got some interesting ones. I hate to say it but it sounds like either the thermostat is stuck open or there is a blockage in the heatercore. You could attempt to flush the heatercore with a garden hose and see if that helps. But I am leaning to the thermostat being stuck open.

As for the stalling issue I am thinking the TPS (throttle position sensor) do you get any check engine lights?

 

[kyle.hand]

Well i replaced the Thermostat and it was definitely stuck open. I also replaced the IAC. It seems to have fixed the problem as of now. It still seems to have a slow idle but it has not died since replacing the IAC and cleaning the throttle body. I have not checked the heater yet.