compression test procedure?

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Mar 16, 2018 | 05:50 PM

cjben

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compression test procedure?

2004 4.6 Diagnosing misfire codes between 2 cylinders. What is the proper procedure to shut off fuel and spark? I have never done it on a fuel injected engine before.

Mar 16, 2018 | 07:49 PM

steve(ill)

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pull the fuse for the fuel pump or trip the inertia switch....... take out all the spark plugs and COPS and set to the side. Hold throttle open when cranking for 5 seconds to measure each cylinder.

Mar 16, 2018 | 11:21 PM

cjben

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Is this engine one of the engines that had problems braking spark plugs in the heads? are there any special precautions I need to take for them to come out easier?

Mar 17, 2018 | 08:32 AM

steve(ill)

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no, spark plug breakage was in the 5.4 motor....... the plugs are buried down in a hole.. best to blow out the hole after COP is off BEFORE you remove the plug. Some like to unscrew 1/4 turn, then shoot some penetrant in the hole and let it set for 10 minutes... I have never had a problem just removing them dry, and cold.