Shola Posted February 21, 2019 Share Posted February 21, 2019 Hello guys. GTCP85-180L does not fire. It does not go beyond 20% rpm and there is no combustion. We have replaced FCU, oil pressure switch, oil sequencing switch, centrifugal switch, igniter plug, exciter yet no combustion. It just rolls but never achieves combustion. Any help please. Quote Link to comment Share on other sites More sharing options...
Ahmer Posted February 21, 2019 Share Posted February 21, 2019 Hello, replace APU fuel atomaizer most probably cause of this component. Quote Link to comment Share on other sites More sharing options...
Ahmer Posted February 21, 2019 Share Posted February 21, 2019 If u replaced all thing plz check or replaced auxiliary start relay. Quote Link to comment Share on other sites More sharing options...
pjvr99 Posted February 22, 2019 Share Posted February 22, 2019 Is the ignitor firing? are you getting fuel from exhaust? Quote Link to comment Share on other sites More sharing options...
Shola Posted February 22, 2019 Author Share Posted February 22, 2019 Thank you very much. We replaced the atomizer. We will replace the auxiliary start relay. Quote Link to comment Share on other sites More sharing options...
Moeed hassan Posted February 22, 2019 Share Posted February 22, 2019 (edited) Plz check ignitor plug if working properly...also check HT lead connecting ignitor plug. Edited February 22, 2019 by Moeed hassan Quote Link to comment Share on other sites More sharing options...
Milat Posted February 25, 2019 Share Posted February 25, 2019 On 2/22/2019 at 4:56 AM, pjvr99 said: Is the ignitor firing? are you getting fuel from exhaust? Yes. We are having fuel from the exhaust. Pls anyone with any further inputs regarding this issue? Quote Link to comment Share on other sites More sharing options...
pjvr99 Posted February 25, 2019 Share Posted February 25, 2019 you didnt mention replacing aux start relay and fuel holding relay. try that. also try replacing 110% overspeed solenoid on back of apu. back to ignitor: can you hear it firing? Quote Link to comment Share on other sites More sharing options...
Shola Posted February 26, 2019 Author Share Posted February 26, 2019 11 hours ago, pjvr99 said: you didnt mention replacing aux start relay and fuel holding relay. try that. also try replacing 110% overspeed solenoid on back of apu. back to ignitor: can you hear it firing? We replaced both the aux start relay and the fuel holding relay. We also replaced the centrifugal speed switch (110% overspeed switch). We heard the ignite firing. We even saw the spark before installing it back into the combustion chamber. During one of the attempts, the APU rpm rose to 32% and got stagnated. The combustion chamber was also hot indicating some combustion. However, the APU couldn't self sustain its operations. We have replaced virtually every component from FCU to oil pump to atomizer. We are however not sure of the integrity of the ignite as we do not have a new one in store. We have placed order for new ignitors for further troubleshooting. Thank you all for your contribution. I think we all can learn one or two things from this experience after we might have succeeded. Meanwhile, kindly keep your suggestions coming. Quote Link to comment Share on other sites More sharing options...
pjvr99 Posted February 26, 2019 Share Posted February 26, 2019 ok. sounds like you got the important bits. when you started troubleshooting, did you set cracking 57 - 63psi? did you remove the control air line from fuel cluster while setting cracking pressure? Have you changed the acceleration/load control thermostat? Quote Link to comment Share on other sites More sharing options...
Shola Posted February 26, 2019 Author Share Posted February 26, 2019 Hello experts. We also have an APU that quits after running for about 8 minutes. Any idea what could be responsible for this discrepancy? Quote Link to comment Share on other sites More sharing options...
Bogi252 Posted February 26, 2019 Share Posted February 26, 2019 How much fuel is in the #2 tank? Quote Link to comment Share on other sites More sharing options...
Shola Posted February 27, 2019 Author Share Posted February 27, 2019 4 hours ago, Bogi252 said: How much fuel is in the #2 tank? It is more than the required 2000 pounds minimum. Quote Link to comment Share on other sites More sharing options...
pjvr99 Posted February 27, 2019 Share Posted February 27, 2019 9 hours ago, Shola said: Hello experts. We also have an APU that quits after running for about 8 minutes. Any idea what could be responsible for this discrepancy? what is part number for this APU? Quote Link to comment Share on other sites More sharing options...
Shola Posted February 27, 2019 Author Share Posted February 27, 2019 1 minute ago, pjvr99 said: what is part number for this APU? Model of the APU is GTCP80-180L. Part Number of the APU is 381116-1-7. Thanks a lot. Quote Link to comment Share on other sites More sharing options...
pjvr99 Posted February 27, 2019 Share Posted February 27, 2019 10 hours ago, Shola said: Model of the APU is GTCP80-180L. Part Number of the APU is 381116-1-7. Thanks a lot. Ok was just curious. Gonna go out on a limb here because we had something similar last year. Try replacing flexible oil hoses to and from the oil tank, and make sure the rigid lines and the tank are clean and free of contaminants Quote Link to comment Share on other sites More sharing options...
Shola Posted February 27, 2019 Author Share Posted February 27, 2019 4 minutes ago, pjvr99 said: Ok was just curious. Gonna go out on a limb here because we had something similar last year. Try replacing flexible oil hoses to and from the oil tank, and make sure the rigid lines and the tank are clean and free of contaminants Thanks buddy. We will try this suggestion and let you know the outcome. Quote Link to comment Share on other sites More sharing options...
Shola Posted March 12, 2019 Author Share Posted March 12, 2019 On 2/27/2019 at 3:32 AM, Shola said: Model of the APU is GTCP80-180L. Part Number of the APU is 381116-1-7. Thanks a lot. Correction please. Model is GTCP85-180L Quote Link to comment Share on other sites More sharing options...
Bogi252 Posted March 27, 2019 Share Posted March 27, 2019 Shola, have you purged the fuel like to the atomizer, just prior to starting? Checked in-line fuel filter PN 7507197? Quote Link to comment Share on other sites More sharing options...
Shola Posted April 13, 2019 Author Share Posted April 13, 2019 Gentlemen, regarding the APU that quits after 8 to 20 minutes, a new centrifugal switch was installed and the APU has been operating properly now. 1 Quote Link to comment Share on other sites More sharing options...
lewisHH Posted November 16, 2022 Share Posted November 16, 2022 On 2/25/2019 at 11:41 PM, Shola said: We replaced both the aux start relay and the fuel holding relay. We also replaced the centrifugal speed switch (110% overspeed switch). We heard the ignite firing. We even saw the spark before installing it back into the combustion chamber. During one of the attempts, the APU rpm rose to 32% and got stagnated. The combustion chamber was also hot indicating some combustion. However, the APU couldn't self sustain its operations. We have replaced virtually every component from FCU to oil pump to atomizer. We are however not sure of the integrity of the ignite as we do not have a new one in store. We have placed order for new ignitors for further troubleshooting. Thank you all for your contribution. I think we all can learn one or two things from this experience after we might have succeeded. Meanwhile, kindly keep your suggestions coming. On 2/25/2019 at 11:41 PM, Shola said: We replaced both the aux start relay and the fuel holding relay. We also replaced the centrifugal speed switch (110% overspeed switch). We heard the ignite firing. We even saw the spark before installing it back into the combustion chamber. During one of the attempts, the APU rpm rose to 32% and got stagnated. The combustion chamber was also hot indicating some combustion. However, the APU couldn't self sustain its operations. We have replaced virtually every component from FCU to oil pump to atomizer. We are however not sure of the integrity of the ignite as we do not have a new one in store. We have placed order for new ignitors for further troubleshooting. Thank you all for your contribution. I think we all can learn one or two things from this experience after we might have succeeded. Meanwhile, kindly keep your suggestions coming. Any update on this , having same issue Quote Link to comment Share on other sites More sharing options...
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