We have a 2012 EL Limited with 120K miles on it that has a nagging long crank on cold start issue. After the vehicle sits about 3 hours it takes 3 to 5 seconds of cranking to get it to fire. Then it runs a little rough for 10-15 seconds or so before clearing up and running normal. Once warmed up it starts fine every time. No codes. Pressure test of fuel system is normal. Recently changed plugs and checked for leaking injectors but that came out negative. MAF is clean. Canister purge valve tested fine. We're planning to downsize and want to sell this rig but need to figure out this problem first. Any ideas?
Long Crank on Cold Start - 2012 EL Limited 5.4L
- Thread starter Mark D
- Start date
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Hamfisted
Full Access Members
Did your pressure test of the fuel rail include a leak down test ? Sounds like the check valve in the fuel pump is bad and it's allowing fuel pressure to bleed down to zero after shutdown. The check valve holds fuel pressure in the line even with the engine off, allowing easy, quick startups even after sitting overnight. You can prime the system just by putting the ignition in the RUN mode (don't crank the engine...) a few times before you actually crank the engine for startup. Try that and see if it improves your cold startups. If it does, you'll have to replace the fuel pump in the tank, or install an in-line fuel check valve to get it back to normal.
5/16" Fuel Line Check Valve at Amazon
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5/16" Fuel Line Check Valve at Amazon
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Thanks for your reply. Yes, the pressure test included a leak down test and showed no loss of pressure over several days. We've tried priming the system multiple times as you suggest with no improvement.
New info, cranking time seems to have been significantly reduced since the weather warmed (50s & 60s in the morning vs 30s & 40s we had just a few weeks ago). There is now only a slight delay, maybe a second or less, before the engine fires. Once running it still seems to idle a little rough for the first 5-10 seconds but then smooths out and runs fine.
New info, cranking time seems to have been significantly reduced since the weather warmed (50s & 60s in the morning vs 30s & 40s we had just a few weeks ago). There is now only a slight delay, maybe a second or less, before the engine fires. Once running it still seems to idle a little rough for the first 5-10 seconds but then smooths out and runs fine.
Dans95tbird
Member
I have the same issue, did you ever get this solved?
