Misfire third sparkplug - 2003 Chevrolet Venture Passanger

This misfire can come from a sparkplug wire, to a sparkplug,As for this is a window feedback, that Ford does not use in there GEM module, satisfy the misfire clear the code and recheck codes

i would check egr valve and check to see if working this will cause misfire codes that you have had /swap sparkplug with another cylinder and see if problem now at another cylinder could be bad spark plug as cause

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 misfire wont pend or code unless the misfire counter exceed 1400.It obviously seeking ground from the sparkplug boot,make it easy on yourself the COP (coil on plug) or the number under the heater hose that may have gotten water in there move that to the front and reinspect the sparkplug boot.

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

-----------
Bad miss at idle?

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

-----------
While stop engine idles like cylinder missing?

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

------------
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

--------------
Misfire on cylinder 4?

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

-----------
Oil on spark plugs and car misfires?

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

----------

This will help.

Thanks.

Could be 1 of 3 things sparkplug fouled,sparkplug wire or a faulty injector or injector wire connector has a poor connection.Also if this engine has 1 coil per cylinder then the coil for that cylinder could be faulty.

A misfire alarm typically means the coil pack mounted above the sparkplug indicated in the misfire had gone defective.

To test it, swap the coil pack with another cylinder, and see if the misfire goes from #2 to the cylinder you put it on.

If the misfire continues to be on #2, then consider changing the sparkplugs.

I hope this helps.

P0300, this is random misfire, or more than two P0135 02 heater circuit malfunction
you need to address the random misfire, it can be a vacuum hose leak a sparkplug wire, or even sparkplugs getting its useful life, as for the P0135 it detecting the engine condition and seeing lean signal as misfire occurs

inspect the sparkplug plug first!! After engine is running for 20 sec (while misfiring), pull your #1 sparkplug and check for fuel. If there is no fuel replace the injector!!If there is fuel, post a comment for more help!!

sparkplug on a diesel????? it is a cyl 7 misfire but n o sparkplugs on diesels