i know we've had issuies with GTC's throughout my 11 years as an engine mechanic but there are a few things that may help that you can adjust on the gtc to help aid in bleed pressure to the manifold. 1st is the acceleration control valve psi. i can't remember the limit off the top of my head but that is within the 49jg in USAF tech data. after making sure that is right next step is to verify fuel cracking pressure. after all that is said and done there is the load control regulator check that with bleed air on the manifold you can adjust what rate of flow the load control puts out. these are all checks that are to be done with the test set installed. i have bypassed this with a pressure gauge and hoses and fittings and doing each check one at a time. since then we have had no issues with flame-outs nor output pressure. with a properly adjusted gtc i can run both a/c packs, atm, and kick on wing/emmp anti-ice without the gtc dieing. i can also start an engine at 95f at sea level off the gtc with atm running and the atm stays online.