misfire code p306

Old 11-08-07, 02:37 PM
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misfire code p306

I have an 1996 blazer with an 4.3 that idles rough,an will set a dct of p306 which is misfire on cyl.#6 i changed the cap, rotor button,wire and plug. out of despration put a plug in #6 wire and there is enough fire to light up the state of texas! where else could the trouble lie
Old 11-08-07, 03:16 PM
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We also have a 96 blazer that keeps dragging us through hell and back....

Have you thought about checking the EGR valve or just replacing it all together. Also check for any vaccum leaks. These can also be another cause of running rough and can cause misfires.

These are a few things coming off the top of my head. I am not a professional but a simple backyard mechanic and have had more than my fair share of issues with this truck.

Now, can you tell me what is wrong with my blazer? LOL It runs rough too. It wants to die "when it wants to" at intersections. And it comes up with a code for the EVAP system. THere's more, but I dont want to take away from your post!

Its a stubborn POS.

Last edited by Dawn-N-Larry; 11-08-07 at 03:19 PM. Reason: info
Old 11-08-07, 05:28 PM
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The after market distributor caps for these engines are junk, MUST put a GM cap on it, the after market caps are molded with the bands for the plug wire terminals too close together and will cause it to miss fire or in some caces not even run at all!! Thats one posability... other could be the Fuel injection spider under the upper intake, these are very , very common problem causers. This engine also has to have around 65 psi of fuel pressure to run correttly. good luck!!
Old 11-08-07, 06:08 PM
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pluged #6 injector maybe?

if ur getting spark to it and still missing i would look at that
Old 11-08-07, 06:08 PM
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Check the basics. You already know you have fire. Now you need to test for fuel and air. Test your fuel pressure and for leaks. Check your air filter and air box for restriction. Check for vacuum leaks. The lack or presence of any of these items can cause misfires.
IF you can find anything with these items its time to check the engine. You need to perform a compression test as well as a cylinder leak down test. These tests are crucial in finding an internal engine failure.
Hope this helps ya,

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