engine misfires

My engine misfires off and on even after a tank of gas with Lucas fuel treatment was used and new spark plugs installed. I suspect an ignition coil is failing. Has anyone had a similar problem. 2006 Tacoma with 181k miles.

 

Are you getting any engine codes?
Or are you feeling it at idle or under load?

 

Scan it.

 

Next step would be to figure out which cylinder is missing...

 

Scanned by Auto Zone. Found nothing even though Check engine was on. I think I’ll have a complete engine scan. Kinda expensive.

 

Misses sometimes at idle and when under load. This problem comes and goes. Maybe several hours, then starts again.

 

I wish I knew a simple way to determine which cylinder misfires. A few years ago I had a SUN timing light that I could clamp on each plug wire for this test. Old school, when troubleshooting was simpler and you could do many repairs yourself. Being an old man (85 in March) doesn’t help.

 

There is but you need a scanner that can read enhanced engine data, misfire counts on each cylinder are available in scan data.

 

Get a buddy.
Start truck
And start unplugging one by one and listen for a difference in the engine
If you pull one and it makes no difference in the idling. “There it is”

 

If they scanned it, found nothing while the check engine light is lit, they either did it wrong or used a really cheap code reader. Many places don’t charge to plug in a code reader.

 

Agreed. Go to auto Zone, advanced auto NaPa…. Or any chain parts stores
they all should scan for free

 

aoonav OBD Check Bluetooth OBD2 Engine Scanner car daignostic Tool for Android,OBD II Vehicle Code Reader Supports Torque, OBD Fusion app

https://www.amazon.com/aoonav-Bluet...utomotive&sprefix=code+reader+,aps,136&sr=1-3

https://shop.snapon.com/product/ZEU...t-Diagnostics-and-Information-System/EEMS342W

Cheap. And not cheap

 

May be a good investment to spend $140 on 6 new coils and a crank position censor. By the time my trucks get close to 200k I have 2 of everything. I can't stand casing codes and spending time worring with 1 part at the time when I need my truck

 

Lol you got the not cheap part right on the SnapOn, I have a Verus Pro (bought used in 2017 for $3000), a Verus Edge (used 2021 $3400), and an Autel MS906BT (new 2018 ~$2000).

You can get a pretty capable scan tool nowdays for under $200, if you want full system scanning, data, and bidirectional controls your gona be in the $300-700 range.
There's also some cheaper ones out there now that offer full system diagnostics subscriptions by vehicle Make for very reasonable prices.

 

My 2005 would misfire (Buck) under a load. Under normal driving it was fine. I changed the plugs and it didn't help. I went back and checked each of the coils and found that one was burnt where it attached to the top of the plug. I ordered a new one through Rock Auto and haven't had a problem since. I am thinking I didn't get it on quite right on my last plug change. Around hitting the 10,000 mile mark it started acting up so I changed the plugs thinking I got a bad set.