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5.3L Tahoe hard to crank

Old Dec 3, 2013 | 10:03 PM
  #31  
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Originally Posted by Suburbazine
Engine running, gauge hooked up, pull the vacuum hose off the regulator. You should see a pressure spike.

If you have a DBW throttle body, you have no IACV. If you have a DBC, it's the small gold round thing on the upper right side. The holes in front of the blade are where the IACV draws from.
Ok I'll try that. I have DBW so that's why I couldn't find it haha

Last edited by 99corvette; Dec 4, 2013 at 07:55 PM.
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Old Dec 6, 2013 | 07:04 AM
  #32  
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I have been fooled a few times by the fuel pressure regulator. I have pulled the vacuum line off 3 times and not seen any fuel. Pulled it off for a 4th time and there is fuel. Put one on it and fixes the problem. Also you could try unplugging the MAF sensor and starting it up. If it starts up fine then there is your issue. Unplugging the MAF will make it start and run off of set values. If you can I would try to use a scantool and see what your coolant temp reads when cold before you start the vehicle. Kinda sounds like the issue. Usually you would get a code but not always.
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Old Dec 6, 2013 | 05:50 PM
  #33  
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Originally Posted by Dangeruss5.3
I have been fooled a few times by the fuel pressure regulator. I have pulled the vacuum line off 3 times and not seen any fuel. Pulled it off for a 4th time and there is fuel. Put one on it and fixes the problem. Also you could try unplugging the MAF sensor and starting it up. If it starts up fine then there is your issue. Unplugging the MAF will make it start and run off of set values. If you can I would try to use a scantool and see what your coolant temp reads when cold before you start the vehicle. Kinda sounds like the issue. Usually you would get a code but not always.
Those are two good ideals. I thought about just replacing the coolant temp sensor. It's only $20. I've pulled the regulator off probably 10 times. I even let it run for 5 mins with it unplugged and never got any fuel.
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Old Dec 6, 2013 | 09:39 PM
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Maf did nothing to mine. But as I was Tryin mine I turned around hitting the shifter up, started right up. Anyone heard of a neutral safety switch goin out like this? I'll try again in the morning when it's cold and see if I can do it again jiggling the shifter.
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Old Dec 6, 2013 | 10:16 PM
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I'm kinda leaning toward intake manifold gasket on mine. Motor warms up gasket swells.
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Old Dec 6, 2013 | 10:18 PM
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That may be my source of the random misfire code on mine.
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Old Dec 6, 2013 | 10:29 PM
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Yep me too. Because I never get a misfire on a certain cyl. But it does have a mis at high Rpms. Also explains why I have to open the throttle blade to get it to crank.
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Old Dec 8, 2013 | 02:34 PM
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Update: rented a fuel pressure checker again. Key turned over just primed and not running got 50psi. Then running got 45psi. Then running with fuel pressure regulator unplugged got 55psi. Sound normal?
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Old Dec 8, 2013 | 03:02 PM
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Originally Posted by 99corvette
Update: rented a fuel pressure checker again. Key turned over just primed and not running got 50psi. Then running got 45psi. Then running with fuel pressure regulator unplugged got 55psi. Sound normal?
It sounds like the regulator is functioning properly.
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Old Dec 8, 2013 | 03:32 PM
  #40  
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I'm gunna unplug it and try to crank it cold and see if there is a difference. I don't think it will change though.
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