Today i was tracking down an intrusion issue for a parts truck i just picked up. i ran a rubber line directly to the fuel tank pick hard line connection to elminate every connection including fsv, metal line, and ran an electric pump to eliminate the mechanical pump. I was still get spurts of air out of filter head. I crawled under the truck and felt all around the connection and found the elbow leaving the sending unit actually had a pin hole leak. I would have never found it without the electric pump constnatly pulling a vacuum on it, i could only hear it every 10 seconds or so. I mixed some quick steel and presed it on it, it started right up and ran fine for the next hour. That was a new one for me, on a 1994 turbo 2wd truck that really didnt have much rust too.
