Silvic
Gold Member
I thought this would be a good place to post this. There is such a large community of knowledgeable folks that maybe someone can help.
A bit long winded but here goes:
I have a piece of equipment (CTL) that has a Perkins engine in it. There is a gauge (LCD style) that displays the inlet air temp. This is not the manifold temp but the inlet to the turbo temperature sensor.
Recently it began a intermittent issue in which the inlet air temp starts dropping moderately fast when the engine is at full throttle. In my application this engine is at full throttle almost full time (except warm ups and cool-downs.) Normally the temperature tracks engine load and throttle directly. When this "drop in temperature" occurs the ECM commands more fuel as it senses that it needs the fuel due to the temp dropping. This results in an unburned fuel smell. If I idle down while it is still dropping it drops below what would be normal for a full power idle down and if the throttle is then increased the temp starts decreasing again. Almost like it is reverse sensing temperature at this point. Once I turn the engine off and let it sit for 10 seconds and restart it, everything reads and runs normal until the next occurrence.
I have talked to the Perkins rep and the service manager of the dealership who happens to be 3 and 5 hours away respectively and they are at a loss as well. No codes are being thrown and that prevents any trouble shooting with codes. There is a Perkins software package that can run some tests but the Perkins facility is 3 hours away and the software is about $5K so I am rather reticent to purchase it. (not certain they would even sell it)
Don't really want to shotgun a temp sensor at the problem ($140). Does anyone know just how an air inlet temperature sensor functions and is it possible with some intermittent malfunction that it could start reading inverse temp/voltage. The Sensor has a 5 volt energizing signal from the ECM but with only two wires I don't know haw it sends data back, unless it plays a plus/minus game with the 5 volts and that is converted to a digital temp reading.
Not only is it annoying, I and the service manager have a concern that long term it will ruin the DPF due to the unburned fuel that is suspected of being the source of the smell.
A bit long winded but here goes:
I have a piece of equipment (CTL) that has a Perkins engine in it. There is a gauge (LCD style) that displays the inlet air temp. This is not the manifold temp but the inlet to the turbo temperature sensor.
Recently it began a intermittent issue in which the inlet air temp starts dropping moderately fast when the engine is at full throttle. In my application this engine is at full throttle almost full time (except warm ups and cool-downs.) Normally the temperature tracks engine load and throttle directly. When this "drop in temperature" occurs the ECM commands more fuel as it senses that it needs the fuel due to the temp dropping. This results in an unburned fuel smell. If I idle down while it is still dropping it drops below what would be normal for a full power idle down and if the throttle is then increased the temp starts decreasing again. Almost like it is reverse sensing temperature at this point. Once I turn the engine off and let it sit for 10 seconds and restart it, everything reads and runs normal until the next occurrence.
I have talked to the Perkins rep and the service manager of the dealership who happens to be 3 and 5 hours away respectively and they are at a loss as well. No codes are being thrown and that prevents any trouble shooting with codes. There is a Perkins software package that can run some tests but the Perkins facility is 3 hours away and the software is about $5K so I am rather reticent to purchase it. (not certain they would even sell it)
Don't really want to shotgun a temp sensor at the problem ($140). Does anyone know just how an air inlet temperature sensor functions and is it possible with some intermittent malfunction that it could start reading inverse temp/voltage. The Sensor has a 5 volt energizing signal from the ECM but with only two wires I don't know haw it sends data back, unless it plays a plus/minus game with the 5 volts and that is converted to a digital temp reading.
Not only is it annoying, I and the service manager have a concern that long term it will ruin the DPF due to the unburned fuel that is suspected of being the source of the smell.
