Changed Tank, ran well, then worse & worse...

[uglytruk]

...so I guess I have air in line. I repaired my rusty tank, '87 'burb, JB Weld is MIRACULOUS! So it started right up, idled for several minutes, drove around the block, started right up in the morning, drove back to my shop, (just around the corner),and then started doing "the dance".
I guess air was in line, as it should be, so opened bleeder on square filter, and fuel stream, air, stream... then runs well, then stalls, yadda, yadda. I removed supply to tank and pressurized tank, no air, watched for leak down towards back of truck, incase fuel line sucking air/leaking. No air in fuel stream, re-attached, bled filter, same deal. It got better, so drove 1 mile to store, stalled and re-started w/ difficulty, then got worse, 10 mins to re-start. I thought air would eventually work thru, but it's getting worse. When it wouldn't re-start, I opened bleeder, and fuel then air under pressure, then it finally re-started.
So obviously I have an air prob. Ran great before I tinkered. Could lift pump have been weak and showing up now? If pump has broken diaphram, I suppose it would suck air. Hate to change for nothing. And I'd prefer genuine AC, not Advance Auto. Can I do a pressure test on pump? Or just bleed lines at injectors first I guess...

 

[imiceman44]

You can do a pressure test on the lift pump, I believe 6-7 PSI is normal

 

[uglytruk]

Found air-in-filter/no start problem...

Boy, did I grind my starter to death! Problem was tiny rust hole above axle, coincidentally right near leak in return line (that I had fixed last week). Took most of the day to figure it out. I finally put a one gallon bottle right on the fuel pump, ran great. Then did vacum test, held 20 inches, put out instant 7 lbs, and held, so pump fine. Put guage on supply at tank and 10 inches, dropped fast. Crawled underneath and found a wet area "hiding" in undercoating & oil on frame. Cut line, slipped rubber over, two clamps, and runs like the good ol days... Whadda' pain not having a hoist!

 

[afroman006]

Well **** least you got it fixed. I plumbed my entire system with rubber hose but its starting to crack in a couple areas where its bent kinda sharply and is near the exhast. I dont intend to do anything about it until it starts leaking though, cause I'm lazy like that.

 

[uglytruk]

I slipped a piece of rubber, (lubed w/sillycone) over rusty area, seen at far right. Then compression fittinged back in place. Onlya few inches were rusty due to heavy undercating. Runs just like old days...