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View Full Version : Slow to start, air in return lines



ThreeQuarter
10-24-2008, 12:39
Lately my pickup has been taking longer to hit & run when I crank the motor. The longer the pickup sits, the longer it will take to run after I start cranking. If I only let it sit overnight, it cranks reasonably quickly; if I let it sit for a week it takes ~15 seconds before the motor will run. The delayed starts are accompanied by large clouds of gray diesel smoke.

My first thought is that air was getting into the high-pressure fuel lines and preventing the IP from building adequate injection pressure. I did not see any "wetness" around any of the fuel lines, injectors, or return lines. I replaced the hose between the metal return line & the injection pump with clear hose. I drove my pickup last night and when I parked it there was no air showing; this morning there was a bubble.

What does this tell me? If the injectors leak down, would that air show up the return line? Any other suggestions for what the root cause might be? Please make suggestions from experience & knowledge--no SWAGs, thanks. Ben

Warren96
10-25-2008, 10:26
Over on the 6.2L forum at the top of the page is the best advice you will ever find on ''Air in the fuel lines; A tutorial" It could probably be posted at the top of this forum, but the same rules apply. Good luck, and let us know what you find ,keep us posted.

ThreeQuarter
10-29-2008, 19:18
That's a good thread, thanks for suggesting it! Found a leak at the inlet to the fuel filter housing & tightened the clamp. Time will tell...