I change all sparkplugs the engine still misfires 2000 jaguard s-type 3.0

im having a problem with my 2000 jaguard s type ,help please ,engine runs fine at idle ,when i press the gas pedal ,the engine cut off

There were a number of problems with V=8 engines in this Series. Some of the sparkplugs would try to leave the engine on their own. You need more testing to know what is wrong.

I will try to explain. The trouble Codes generated by your Onboard computer can be too general to identify a specific part for some problems.

There are 3 causes for a misfire. Fuel, spark, and compression. You can have fuel injectors which are dirty or have bad connections or coils and fail to open consistently. Spark issues are more complicated to diagnose as coils are now attached to individual sparkplugs(some models) and are triggered by Crankshaft and Camshaft sensors. A bad coil-pack feeding each bank of sparkplugs can short out adjacent plugs like #3 and #4.

Compression problems between #3 and #4 cylinders from a bad head gasket can cause misfires.

You can get a loaner test kit for the fuel injectors or use a test light or multi-tester. This will eliminate or confirm the fuel injector circuit as the problem.

There are cylinder balance tests that are non invasive when done with a good scanner. Otherwise removing the sparkplugs will be required to do a compression test.

Sparkplugs leaving the engine: They either unscrew or rip out the sparkplug hole. Loose plugs will misfire. BUT there is a problem with removing sparkplugs on these Series of motors. The factory plugs are 2 pieces welded together. Carbon buildup causes the sparkplugs to come apart as they are removed. Use solvent every 1/4 turn, let set for first 2 twists.

There was a Recall on these motors, but a Mileage limit and a time limit of about 7 Years was imposed. Check Internet for articles about all of these subjects, photos, etc.

Please rate my info.

The sound you are hearing is a spark arcing from something powering the #3 cylinder. It can be a cracked distributor coil, bad sparkplug wire, bad coil on plug or cracked sparkplug. It can also be the wiring going to the #3 fuel injector, or a defective fuel injector.

Sometimes if the engine is cranking, in a dark garage, you can see the spark jumping. You probably get less problems once the engine dries out from operating, unless the part is severly shorting out.

If you can not visibly see a problem(arc flashing) then you will need to change the parts until you do find the bad one. The onboard computer needs to be cleared after the parts are changed, free clearing services at Autozone, Advance, or Oreilys.

I would start with the cheapest parts, like the sparkplug, sparkplug wire, and/or coil. Some plugs have coils on each individual plug, others have coil-paks for each engine bank.

You would pretty much be doing what any mechanic would have to do. The best info you are going to get out of the onboard computer is which cylinder is misfiring, not which individual component is bad for your type of problem. Sometimes a mechanic will replace several items to save time and be done with it. You have to remove too much stuff to replace adjacent items 3 times.

I hope my solution is helpful.

For engine misfiring problem check the help links mentioned below. Click the link below to go through the troubleshooting procedure :---- Engine misses and truck jumps? Hard to down shift? Issue with high gear only? http://technoanswers.blogspot.in/2012/02/engine-miss-and-truck-jumps-hard-to.html

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Bad miss at idle?

http://technoanswers.blogspot.com/2012/01/bad-miss-at-idle.html

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While stop engine idles like cylinder missing?

http://schematicsdiagram.blogspot.com/2012/01/while-stop-engine-idles-like-cylinder.html

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Engine Misfire codes for car?

http://schematicsdiagram.blogspot.com/2011/12/engine-misfire-codes-on-chevrolet.html
Engine Misfire codes?

http://schematicsdiagram.blogspot.com/2011/12/engine-misfire-codes-on-chevrolet.html

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Misfire on cylinder 4?

http://schematicsdiagram.blogspot.com/2011/12/misfire-on-cylinder-4.html

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Oil on spark plugs and car misfires?

http://technoanswers.blogspot.in/2012/02/oil-on-spark-plugs-and-car-misfires.html

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This will help.

Thanks.

Random misfires usually happen when the spark jumps from one wire to another out of sequence. The cause can be bad wires or you can have a cracked coil-pak. The coil-pak can be bench checked at some autoparts stores. Another possible problem is the Crankshaft sensor which lets the engine know the position of the crankshaft before firing the sparkplug.

Sometimes you can observe the wires arcing when the engine is running in the dark. You may also be able to mist the engine with water using an old spray bottle. The wires should be well enough insulated to withstand the extra water and if the wires don't they need to be replaced.
The Code for a Random misfire may eventually set to the problem sparkplug wire or plug. Even knowing which side of the engine is causing the misfire can help to narrow down an individual coil-pak or wire.

Your description indicates the ignition module located right below the coil packs.

check your distributor

Inspect #2 spark plug and the ignition wire to it. Inspect the connector to the plug and to the coil... replace as needed.

yes about the upper intake and the only way i know how to check the coils is with a engine anilyser or if the check engine light comes on then you can have the codes pulled and that will tell you which cylender is missfiring this engine has a indevidual coil for each spark plug so thares 6 of them and thay slide right down over the sparkplugs

Possibly coils check compression make sure the plugs are the proper ones some engines are particuler about the plugs