Jump to content
Aero Precision provides OEM part support for military aircraft operators across more than 20 aircraft
Shola

GTCP85-180L APU does not attain combustion

Recommended Posts

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.

Share this post


Link to post
Share on other sites

Thank you very much. We replaced the atomizer. We will replace the auxiliary start relay.

Share this post


Link to post
Share on other sites
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? 

Share this post


Link to post
Share on other sites

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?

Share this post


Link to post
Share on other sites
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.

Share this post


Link to post
Share on other sites

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?

 

Share this post


Link to post
Share on other sites

Hello experts. We also have an APU that quits after running for about 8 minutes. Any idea what could be responsible for this discrepancy?

Share this post


Link to post
Share on other sites
4 hours ago, Bogi252 said:

How much fuel is in the #2 tank? 

It is more than the required 2000 pounds minimum. 

Share this post


Link to post
Share on other sites
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?

 

 

Share this post


Link to post
Share on other sites
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. 

Share this post


Link to post
Share on other sites
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

Share this post


Link to post
Share on other sites
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. 

Share this post


Link to post
Share on other sites
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

Share this post


Link to post
Share on other sites

Shola, have you purged the fuel like to the atomizer, just prior to starting?  Checked in-line fuel filter PN 7507197? 

Share this post


Link to post
Share on other sites

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. 

  • Like 1

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...