Sticky thermostat/temp sensor

[gregorys1989]

There has been a couple cool mornings in the last week "only about 50 or 60 degrees" so nothing too bad. But my trucks been trying to stall and or stalling on the initial cold start. When turning the key over after the stall she starts perfect. Ive been suspecting its something with the cooling system in the car because my temp gauge starts at the furthest it can drop down and in normal weather conditions it only warms up to the break of the normal line. Mind you it takes a good fifteen minutes of driving to get there, and if its cold even longer. No cell light unless it stalls out on the initial start up. Also before it stalls the battery voltage starts fluctuating back and forth right before it stalls. When warmed up she runs like a champ though. Just replaced the coolant temp sensor had the battery off throughout the process of installing it which took about twenty minutes then hooked it back up and it did the same thing. Whats your take on this? did i install the sensor properly? Furthermore, my coolant is very rusty, i tryed to flush it myself and it just came back after about a week of driving.....thermostat?

 

[Earl43P]

Cold start issue like you describe is usually that the fuel pressure has dropped off.

Try turning the key to Run, do not crank the starter.
Wait 2 seconds as fuel pump hums and builds up pressure.
Turn key to Off.
Repeat and wait the 2 seconds, THEN crank over the starter.

If that works, your fuel pump checkvalve may be bad or a leaky injector is stuck partway open or the fuel filter fittings are seeping, letting fuel pressure bleed down overnight.

 

[gregorys1989]

thanks, that was also a thaught of mine. What i dont understand is why it only does it when its cool out. If i let it sit overnight and its 80 degrees when i start it, it will not stall

 

[gregorys1989]

I started my truck at a warmer point in the day and it still stalled. so the fuel pressure is definitely something i need to investigate. but the temp sensor didn't seem to change anything, although i still have eradic temp readings, i need to change the thermostat to get a better idea. Could there possible be a bad connection in the temp sending unit?

 

[gregorys1989]

in the midst of a nightmare changing the thermostat. went to change it and the thermostat housing bolts cracked off and the threads are fused to the intake. ahhh. have it at the shop now having them change the rest of the thermostat and theve been trying to get the bolts off for some time now and its not looking good

 

[locovaca]

in the midst of a nightmare changing the thermostat. went to change it and the thermostat housing bolts cracked off and the threads are fused to the intake. ahhh. have it at the shop now having them change the rest of the thermostat and theve been trying to get the bolts off for some time now and its not looking good

Yup, that happened to me. Start calling junk yards for a new lower intake, it's the easiest and cheapest thing to do. I pulled complete intake for $40.

 

[gregorys1989]

yeps. I have awsome luck had to replace the intake to get the bolts out. but atleast I was right about my thermostat. it was stuck open. Runs much better now