4.6 won't start
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4.6 won't start
Today got in car and it started for 1 second, then died. Will not start again. Prior to this happening, the last day I drove it it seemed to stall a couple of times, lurched forward and would go. I have spark, the starter is turning, but no clue from there. How do you test the fuel pump? Thanks.
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Joined: Feb 2008
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From: Chicago Area, Illinois
the first thing i would do is turn the key to the run postiton and listen for the pump to kick on, it'll run for about 3-4 seconds and shut off with the engine off. if you cant hear that that check for voltage to the fuel pump relay (should be under the hood) and check all fuses. if you have voltage to the pump and it dosent kick on, chances are that its a failed fuel pump. if it is working, theres a schrader valve somewhere on the fuel rail on the engine, you'll need a fuel pressure gauge to measure that, cycle the key on and off to measure the pump output. the problem you are describing could be the result of a bad crank position sensor. if the fuel system is working correctly i would chase down electrical problems. by the way what year is the vehicle and how many miles??
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Today I replaced the crank sensor and still no start. I'm getting a decent spark to the plugs. When we turn on the key I don't hear the fuel pump run but how could it keep 40psi at the schraeder valve. Essentially I have spark, fuel but not to the plugs and plenty of air. Any ideas are appreciated.
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4.6 DOHC. No fuel sample taken. How do I know if the injectors are allowing gas into the cylinder? Is there a test or do I pull the injector and test with a voltmeter?
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Today replaced the camshaft position sensor and it worked. Engine started, ran a little rough at first, then smoothed out. Friend of mine said the crankshaft senosr controls the spark, the camshaft sensor controls the injectors. For about $40 bucks, I fixed the problem. Thanks for your help Mercman.
Elder User
Joined: Feb 2008
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From: Chicago Area, Illinois
im glad i was able to point you in the right direction, its good to hear that you were able to get it running! it annoys me that somthing so small (a sensor) can make the whole thing not work lol! take care!