Misfiring?

Hello ANGELA GALLACHER,

Sometimes sludge or other things in you oil can clog the VVT solenoids since they are operated hydraulically.

My advice, I would remove the VVT Solenoid, clean with electrical cleaner (I will add an image of what I use for you) and set aside and let fully dry before re-installing.

While it is drying, I would change the oil and put a fresh filter on it. Not all filters are created equal, so I would use one that is more compatible with your vehicle.

I have found an A/C Delco one for you on Rock Auto. Here is the link:
https://www.rockauto.com/en/catalog/chevrolet,2003,trailblazer,4.2l+l6,1412277,engine,oil+filter,5340

If the oil is dirty or has particulates in it, it will keep this valve from getting proper pressure and affect valve timing.

You may have to do a couple oil changes at about 1500 miles instead of 3000k to really get all the stuff out of the motor. Make sure the filter is changed each time and use good oil like Castrol or Penzoil. Mobile one is a good brand as well.

This essentially will flush the motor and keep this from happening in the future.

Try it out and let me know your results. I think because these apply hydraulic pressure and have very small openings, looking at and replacing the oil is the best first step.

I am also adding the oil I use but it is worth it. I have a 2001 Suburban and this oil makes it run so much better.

You might want to use store brand for the first oil change so it is cheaper because you will be just throwing it out after 1,500 miles.

Then change it again and use the good oil. This time run it for the 3,000.

Let me know if I can clarify anything for you.

Hope this helps and hope you have a Happy 4th!

Thank you,
Brendon

Hello ANGELA GALLACHER,

I'm sorry I forgot to add the picture of the cleaner you should use.

I have added it now for you.

I recommend using this so nothing is damaged.

Thank you,
Brendon

It turns out it was the intention coils all along. I forgot to review the order of the cylinders and so I kept replacing the wrong ones. Once I finally put the coil in the right number cylinder the problem was solved. Ugh! It was a PEBSAS problem. (Problem Exists Between Steering and Seat.)

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