my pyrometer never fully goes down to zero it will hang at 200 when the truck is turned off. and never goes below 400 when cooling down. Is this more of an issue with the gauge or the thermocoupler and associated wiring? is there any type of calibration that can be done to it? the previous owner installed it and i do not have any of the paper work. it is a autometer ultralite series.

 

zack the gauge should never go back to zero because we do not live in absoulte 0 degrees

 

even with no power going to it? it does drop from say 400 to 200 when i shut down

 

Mine does the same thing. You are not going to get much cooler then 350 while engine is running. The next time you start your truck cold check the air temp outside and I bet it will match with key in run position with out firing engine. If its 50 in the morning My pryo will read 50. When I first installed it I put a drop light on the exaust manifold for a while and it went up. Mine hangs a 200 when key is off. Resets when key is on.

 

just went out and check it now. truck has not ran all day. read 200 with the key on run and not started only about 72 outside. with the key off it reads like 125. after running for about 30 seconds it shot up to about 450 and stayed there. seems like everything is a little high

 

I read in my directions not to cut sensor wires to shorten them.. It messes up the calibration. I would think he would have read that also. Check again in the morning after there has been no sun beating on the hood. I know its a streach by would try it just the same. I also had a gauge flutter problem on mine and all I had to do is run a ground wire to the battery from the gauge. A good body ground was not good enough. good luck. You could also call or email autometer directly. They were very nice and helped me.

 

Mine is the same

 

I drove mine today it was around 70 degrees out. I let truck idle for 5 min after driving and the temp went down to just over 300. Like 310. So I would agree that 450 after start up would be a little warm. Mine is mounted pre turbo.

 

Thermocouples and pyrometers don't measure absolute temperatures but rather temperature differences from one end of two different-material wires to the other. They also require no power to operate. They are essentially a very sensitive volt meter. So "theoretically" it should return to zero. That said, mine doesn't. It hovers around 200 when the engine is cool. But mine does get below 300 while idling. My Isspro cool-down unit won't shut the engine down until it has reached 300.

 

i never seen it go below 300 when cooling down. i will sit there for 5 mins after driving and it will only drop to about 450-500. mine is also mounted pre turbo. i guessing something is messed up with the pyro.

the previous owner screw up in his placement of the probe and put it directly in the center of the manifold (it is now in the correct location). could the probe have gotten messed up from being against the divider in the exhaust manifold?

 

mine shows 62 in the mornings. then after that i never really see it go below 129 degrees the rest of the day. when cooling down i cool mine off to 250-275 before i shut off...only takes a few minutes to drop..

 

I heard the probe is sopposed to be placed at the manifold in the center is this wrong my truck is a 93 with a innercooler???

 

There is a divider wall in the center of our exhaust manifolds. Do not try to center mount a thermocouple. Most install it in the the rear 3 cylinder section of the manifold.

 

No, in the center there is a divider in the exaust manifold. Somewhere on here there is a placement guide. I believe it measures 2 inches twords the drivers side from turbo and 5/8 's of an inch twords firewall from center.

 

Philip, you type faster then me... You beat me to it.