So my 7 was in the shop (Mazcare in marietta) for a week. I had told them sometimes my second turbo would choke and all power was lost. They found a different way of reproducing it than a straight line, so that helps troubleshoot I suppose. But it had been doing this about 40% of the time.

So when I dropped it off they cleaned out all the vacuum lines (clogged with oil, turbos leaking, but still boosting!) checked solenoids and actuators and stuff, but could not determine a solution to the problem without having to replace the turbos.

A week goes by and I want my car back so I get it and am going to drop it off later on again. It still runs fine for 2 days. Then, the second turbo choked again. And continued to do it once in awhile.

So, I was givin' her some go to 7500, shifted from 1st to 2nd and I noticed my boost guage had stopped working. I noticed that it ran smoother while this hose was off. So, then I but the hose back on the intake manifold and put a clamp on her.

Guage is working, all is going well, until it chokes again! The next day i remove the hose and it runs sooooo much better. Turbos spool fast and properly. I can even notice a speed increase.

Is it bad to have the hose just sitting there and any ideas what the hell is going on??

Edit: also it idles correctly at 720 when the hose is ON and the idling fluctuates from in between 720 - 1100 when the hose is OFF. I am pretty sure I can feel back pressure while idling at 1100 too.

 

Update: I have had the boost guage hose off for a week and now the turbo is choking in 1st again

 

without a cap on the manifold nipple you are sucking in air under vacuum. Air includes dirt and dust and an unhappy motor. We have all driven around w/ loose vac lines tho and I don't know of any motor failures due to crap inhalation due to it