Engine Cylinder misfire

Tiny
SCGRANTURISMO
  • MECHANIC
  • 4,897 POSTS
Hello,

This could be caused by a few different things, but I would check the ignition system first. I have included these links for you below. Go through them and get back to us with what you find out.

https://www.2carpros.com/articles/engine-misfires-or-runs-rough
https://www.2carpros.com/articles/how-to-test-an-ignition-system
https://www.2carpros.com/articles/how-to-test-a-fuel-injector

Thanks,
Alex
2CarPros
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Saturday, December 19th, 2020 AT 9:45 AM (Merged)
Tiny
BMDOUBLE
  • MECHANIC
  • 1,139 POSTS
Unbolt that coil with a 7mm socket hold the end of the boot near a metal stud and it should put out a one inch spark. Easiest way to check it. Also, make sure there isn’t any coolant in the hole when you pull out the coil. Let us know what you find and we can go from there!
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Saturday, December 19th, 2020 AT 9:45 AM (Merged)
Tiny
JDL
  • MECHANIC
  • 16,098 POSTS
Another thought, you might be able to use digital multi-meter, see if you can get inductive reading, each coil, engine running. You don't unplug anything or pierce anything, you just touch the coil. You might get a reading of.5 volt not even a full volt. The point is, if you get a reading bouncing off zero, that's where you start testing, at that coil. Different makes and models may have slightly different readings. Just a thought.
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Saturday, December 19th, 2020 AT 9:45 AM (Merged)
Tiny
KEVIN GODWIN
  • MEMBER
  • 53 POSTS
  • 1999 LINCOLN TOWN CAR
  • 120,000 MILES
Multiple cylinder misfire, no codes, cylinder contribution test shows skip on different cylinders every time I drive, only skips under light throttle going up hill, has coil on plug 4.6, coil or plugs help it
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Saturday, December 19th, 2020 AT 9:45 AM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Check the basics. I would look at the plugs and coils. How many miles are on these items?

The injectors may also be an issue. They need to be professionally cleaned every 50k

Roy
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Saturday, December 19th, 2020 AT 9:45 AM (Merged)
Tiny
KEVIN GODWIN
  • MEMBER
  • 53 POSTS
Injectors are clean and pass flow test, coils and plugs are new
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Saturday, December 19th, 2020 AT 9:45 AM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Ok, start with a compression test

Roy
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Saturday, December 19th, 2020 AT 9:45 AM (Merged)
Tiny
KEVIN GODWIN
  • MEMBER
  • 53 POSTS
Compression is good and timing chains are not stretched
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Saturday, December 19th, 2020 AT 9:45 AM (Merged)
Tiny
LBARAZAN
  • MEMBER
  • 4 POSTS
I have same troubles TC 1999 multiple misfire cylinder #4, 5, 6, and 8
what is causes of this troubles
is this a common trouble to TC model 1999?
I already check and simulate the following.

# Spark test at all cylinders. 4, 5, 6, 8 NO SPARK
# Simulate ignition coil and spark plug and fuel injectors. Crank sensor, cam sensor
same troubles occur no spark at cylinder 4, 5, 6, 8
# Continuity check wiring ign. Coil terminals---OK
#Simulate pcm, same trouble occur misfire 4, 5, 6, 8

compression is oky too.
NO codes given

please guide me and asking for any idea.

Thanks
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Saturday, December 19th, 2020 AT 9:45 AM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
Do you have voltage to the ignition coils?

Does the check engine light come on with the key on, engine off?

Did you check the wires back to the PCM?

Roy
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Saturday, December 19th, 2020 AT 9:45 AM (Merged)
Tiny
LBARAZAN
  • MEMBER
  • 4 POSTS
The number of cylinder no spark are #4, 5, 6, and 8.
I already did switching the following.
Spark plug. Ignition coil. Fuel injectors. And still problems occurs no spark at ignition coil 4, 5, 6, 8.
I do compression test and the result is good compression.
I do check short to power and grounds. Result is oky too
what is next things to do?
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Saturday, December 19th, 2020 AT 9:45 AM (Merged)
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,797 POSTS
OK, did you verify power to the coils that are not firing?

What voltage did you have a t the coil with key on?

Roy
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Saturday, December 19th, 2020 AT 9:45 AM (Merged)
Tiny
ADAMJEFF911
  • MEMBER
  • 2 POSTS
  • 1999 LINCOLN TOWN CAR
  • 4.6L
  • V8
  • RWD
  • AUTOMATIC
  • 105,000 MILES
I had a code that read misfire in cylinder 1, it usually misfires once the engine is no longer cold.

I replaced my spark plug for cylinder 1 and the check engine light and misfiring completely went away and the car drove new. Three days later, the code came back, and it was in fact cylinder 1 yet again. I have checked the gap and it is perfect.

I am hoping to get rid of my misfire before something serious happens.

Thank you very much for your time,
Adam
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Saturday, December 19th, 2020 AT 9:45 AM (Merged)
Tiny
CARADIODOC
  • MECHANIC
  • 33,874 POSTS
Switch the two ignition coils between cylinder number one and one other one, erase the fault code, then see if the misfire code sets for the other cylinder. If it's still for number one, switch two injectors and try again.
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Saturday, December 19th, 2020 AT 9:45 AM (Merged)

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