Another "can't start" thread - Jetcat Titan
11-28-2017, 10:35 PM
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Another "can't start" thread - Jetcat Titan
I've done everything I can think of and I can't get my Propane start Jetcat to complete the start sequence. V6 ECU. I either get a "temp fail" due to the high temp a few seconds after the Kero ignites or (after I change the accelr1 setting) I get a low-RPM after the Kero ignites and the system is trying to stabilize.
- I've replaced the probe already
- I've reset the ECU already
- The turbine throws flames at startup, even after I've lowered the accelr1 pump voltage to the very lowest setting. Owner advises that it's always thrown flames with no problems running.
1. I've tested the fuel pump at all voltages and it pumps a steady flow of fuel, decreasing intensity as I lower the voltage. However if the remedy to reduce the flames at startup is to lower the initial pump voltage, it appears that there is still too much fuel coming from the pump at the lowest voltage setting. Here is the video of the lowest voltage setting for the fuel pump test. Does this seem correct?
From what I gather it seems like the chamber is being flooded at startup. The flames cause a temperature increase beyond 950 deg causing a temp fail or a low-rpm condition since the turbine isn't burning the fuel efficiently. Is this a sign of a failing fuel pump? (I hope so )
2. I've tested the fuel solenoid but I'm not entirely clear on what I'm looking for. I note that it holds open until I release the button, but it does not behave like the propane solenoid that modulates open and shut (clicking) while I hold the button. Do these solenoids perform differently as tested?
When I received this turbine the first few starts I would get the temp fail message. I turned down the accer1 and then it started a few times with no problem.
Any thoughts?
- I've replaced the probe already
- I've reset the ECU already
- The turbine throws flames at startup, even after I've lowered the accelr1 pump voltage to the very lowest setting. Owner advises that it's always thrown flames with no problems running.
1. I've tested the fuel pump at all voltages and it pumps a steady flow of fuel, decreasing intensity as I lower the voltage. However if the remedy to reduce the flames at startup is to lower the initial pump voltage, it appears that there is still too much fuel coming from the pump at the lowest voltage setting. Here is the video of the lowest voltage setting for the fuel pump test. Does this seem correct?
From what I gather it seems like the chamber is being flooded at startup. The flames cause a temperature increase beyond 950 deg causing a temp fail or a low-rpm condition since the turbine isn't burning the fuel efficiently. Is this a sign of a failing fuel pump? (I hope so )
2. I've tested the fuel solenoid but I'm not entirely clear on what I'm looking for. I note that it holds open until I release the button, but it does not behave like the propane solenoid that modulates open and shut (clicking) while I hold the button. Do these solenoids perform differently as tested?
When I received this turbine the first few starts I would get the temp fail message. I turned down the accer1 and then it started a few times with no problem.
Any thoughts?
11-29-2017, 01:53 AM
#2
Are you sure the fuel valve is closing, with everything off can you blow fuel through the fuel valve?
You 100% the valve is in the right pins, I guess if the test works it is. Clicking on fuel and machine gun on gas is normal
Dave
You 100% the valve is in the right pins, I guess if the test works it is. Clicking on fuel and machine gun on gas is normal
Dave
11-29-2017, 08:23 AM
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- OK will get home tonight and blow through the fuel valve.
- Also I noted that during the propane starting stage the temp held at around 280 then of course increased as the Kero started running. A theory I have is that the chamber is not getting hot enough to burn the Kero efficiently at the beginning stage. Thus the introduction of more Kero causes the flames as the turbine spools up due to flooding. *Can anyone tell me what their temp is right before the Kero starts flowing?
- *I'm under the impression that the lowest voltage setting on the fuel pump should just be barely dribbling fuel. Is this true?
- Also I noted that during the propane starting stage the temp held at around 280 then of course increased as the Kero started running. A theory I have is that the chamber is not getting hot enough to burn the Kero efficiently at the beginning stage. Thus the introduction of more Kero causes the flames as the turbine spools up due to flooding. *Can anyone tell me what their temp is right before the Kero starts flowing?
- *I'm under the impression that the lowest voltage setting on the fuel pump should just be barely dribbling fuel. Is this true?
11-29-2017, 06:54 PM
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FINALLLLY !
figured it out, it was actually a bad UAT. These turbines are strange, the behavior and symptoms don't always match to the root cause (of course unless you have plenty of experience to know better)
I was basically getting a virtually undetectable amount of air in the UAT which was JUUUUUUST enough to "almost" get the turbine running. So the lack of good fuel supply caused the low RPM failure.
figured it out, it was actually a bad UAT. These turbines are strange, the behavior and symptoms don't always match to the root cause (of course unless you have plenty of experience to know better)
I was basically getting a virtually undetectable amount of air in the UAT which was JUUUUUUST enough to "almost" get the turbine running. So the lack of good fuel supply caused the low RPM failure.
