2001 4.6L NO SPARK on all 8 - need help
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Joined: Jun 2007
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2001 4.6L NO SPARK on all 8 - need help
2001 F-150 4.6L
I just had this engine rebuilt and now I am putting the engine back in the truck and attempting to start it.
It turns over but gives no sign of being able to start.
I have fuel pressure at the fuel rails.
I pulled a coil pack and did a spark check - it's dead.
I pulled the primary side of the coil to check for voltage. There is Positive voltage on the connectors with the ignition on. I did a test with a test light connecting one lead to battery positive and the other to the neg side of the coil pack connector. When it is cranked over like this - it shows no sign of having an input pulse. I checked two connectors - same story. I conclude all 8 are in the same condition.
I next checked the camshaft position sensor: One book says you can pick up a small voltage on the leads if you pull the sensor out and run a metal object by it repeatedly. The camshaft sensor did not seem to respond. I purchased another sensor and installed it. This one showed more response when the same test was applied. However, upon installing it the spark condition at the plugs is unchanged.
I checked for voltage at the camshaft position sensor leads. With the ignition on there appears to be a very small voltage (.5 to 1v) on one of the leads. I have a book that says there should be 12volts available on one of the sensor leads. Is this correct? If so, it's not there?
I am also suspecting that it may be possible that the camshaft sprocket was installed incorrectly during the rebuild so that perhaps it is not able to trigger the sensor and thereby disabling the entire system from firing - but I don't know this for a fact. Will the codes show whether the sensor signal is missing ?
Also, I am wondering whether I have an open circuit on one of the sensor wires but don't know where it terminates in order to check it.
How should I proceed?
I am thinking if I take this in somewhere I will get charged an arm and a leg and find out it was something simple. Do you know what I mean ? If you're familiar with these systems your help would be very greatly appreciated. Thanks!
I just had this engine rebuilt and now I am putting the engine back in the truck and attempting to start it.
It turns over but gives no sign of being able to start.
I have fuel pressure at the fuel rails.
I pulled a coil pack and did a spark check - it's dead.
I pulled the primary side of the coil to check for voltage. There is Positive voltage on the connectors with the ignition on. I did a test with a test light connecting one lead to battery positive and the other to the neg side of the coil pack connector. When it is cranked over like this - it shows no sign of having an input pulse. I checked two connectors - same story. I conclude all 8 are in the same condition.
I next checked the camshaft position sensor: One book says you can pick up a small voltage on the leads if you pull the sensor out and run a metal object by it repeatedly. The camshaft sensor did not seem to respond. I purchased another sensor and installed it. This one showed more response when the same test was applied. However, upon installing it the spark condition at the plugs is unchanged.
I checked for voltage at the camshaft position sensor leads. With the ignition on there appears to be a very small voltage (.5 to 1v) on one of the leads. I have a book that says there should be 12volts available on one of the sensor leads. Is this correct? If so, it's not there?
I am also suspecting that it may be possible that the camshaft sprocket was installed incorrectly during the rebuild so that perhaps it is not able to trigger the sensor and thereby disabling the entire system from firing - but I don't know this for a fact. Will the codes show whether the sensor signal is missing ?
Also, I am wondering whether I have an open circuit on one of the sensor wires but don't know where it terminates in order to check it.
How should I proceed?
I am thinking if I take this in somewhere I will get charged an arm and a leg and find out it was something simple. Do you know what I mean ? If you're familiar with these systems your help would be very greatly appreciated. Thanks!
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