I just installed 4 rebuilt injectors got them from a friend in the auto business for cost. I just got the car running after changing the fuel line from the filter to the injectin pump , had to take off the manifold etc so it was a big job for me. Got it started again and drove and filed her up at $4.19 a gal.! checking to see if all was well I noticed fuel in the injectors 2 are flowing up pretty very quickly and bubbling. I got her home and checked the fuel line brass nuts and 1 of them is spinning around and the injector is moving with it, I`m positive I tightened all of them and double checked again as always, I`m going out now to work on it any theries on why this would happen ,also I had the other 2 done at a differant shop last month for lack of funds and they are fine.