Hey, Scotty I have a question, I have 2005 Scion xa with 120000 miles. I recently changed spark plugs on the car, but when I start up the car in morning, the engine feels like it’s misfiring. But then it goes away. One time I had check engine when I started it up, but now I don’t see that, but I can hear it misfire. What should I do in this case ?
I recently changed spark plugs on the car, but when I start up the car in morning, the engine feels like it’s misfiring.
Did you torque them properly? You really should use a torque wrench. I changed spark plugs without a torque wrench in my '79 Pontiac and a few months later, it started running funky until it warmed up- the spark plugs had worked loose after tightening them with a regular ratchet.
Yes I have done that. I have a torque wrench. So I torqued it to proper spec.
Take the offending spark plug back out and measure it with a gauge that can be found at AutoZone, on the counter. It's a spark plug measurement reader. I'm having a brain fart. It's around the size of a half dollar.
I did that and it is in spec.
If your plug is gapped and torqued correctly and cylinder 2 still misfires, swap the #2 coil with one of the others and see if the misfire moves to that cylinder. If so, the coil is failing. If not, swap the #2 plug with another cylinder and see if the misfire follows the plug. If so, the plug is bad. Good luck.
Now I am feeling the hesitation only during cold start up and when I drive the vehicle I can feel the hesitation. But after engine warms up and after being driven for little bit. Then everything is alright. What can that be?
You could add some of the ATS fuel system cleaner to your tank and see if that helps. If not, and you are still getting a misfire on only one cylinder, try swapping fuel injectors with another cylinder and see if the misfire moves. If you haven't already, clean the throttle body and MAF sensor after watching Scotty's video on making your car run better with a little spray cleaner. If you have a scan tool, look at your live data and see if anything looks off, especially fuel trims. Good luck.
What brand of spark plugs did you use? And from what seller?
I have seen multiple videos regarding fake NGK spark plugs, and I suppose there could be counterfeits of other brands as well.
For example:
I bought it from auto zone. The Bosch double Iridium