12:30PM, Friday, February 3, 2017
It turns out that UPS dropped off my unit at FiTech at about 9:39AM on Wednesday and then Fedex shows the shipment being ready for pickup at FiTech at 12:26PM, less than 3 hours later. Cody, from FiTech, was supposed to call me yesterday with info about what was found wrong with it but so far, as of 12:30PM on Friday he has not. I did talk to him late yesterday and he assured me he would find out what happened and let me know. I called there this morning and talked to Bryce, another of the tech support guys, and he knew about the unit and that I was looking for answers. He promised to call me back but, so far, he has not either. I am thinking that it must be some sort of manufacturing defect that they saw immediately and corrected. Why else would they be reluctant to tell me?
Back to brakes. Dave Lenzi (he is an amazing designer and machinist who makes and rebuilds GMC parts) suggested that I reconfigure my vacuum pump setup to keep the pump from cycling and running unnecessarily. What he suggested is that the vacuum sensing switch should effectively be sensing the vacuum on the booster side of the check valve because, otherwise, a leak in the check valve in the pump itself will cause it to keep running. I made that change by removing the check valve from the booster port (Dave’s rebuilt boosters have dual ports) and replaced it with a 1/2″ to 3/8″ straight adapter, used 3/8″ hose to get to the vacuum switch, then back to 1/2″ for the vacuum check valve that was in the booster. I am buying Dave’s adjustable vacuum switch and adding a vacuum gauge (I got one from China for $5 on Amazon) so I can adjust it to come on at 16″ and turn off at 18″.
I just got an email from Cody at FiTech that basically says that they could not find the problem. Says they put it on the test engine and “did not find a major fueling issue like you stated” but the put it on the “test bench” and ran a bunch of tests, burned new code into the ECU and then tested it again. It ran “flawless”. If it ever arrives like it is supposed to tonight I will reinstall it tomorrow and give it another try.