testing ignition coils

Reply Subscribe

Thread Tools

Search this Thread

Jan 9, 2011 | 11:12 AM

DOC1KOC1

Thread Starter

New User

Joined: Mar 2006

Posts: 21

Likes: 0

testing ignition coils

I have an '05 f150 w/5.4l that engine is skipping...I want to check the ignition coils. Can I simply ohm them out? I have done that on a '98 5.4l. But the Haynes has nothing stating what the reading should be...Any imput?? I have done searches in the forum but cannot find what I'm looking for.....Thank You...........DOC

Jan 9, 2011 | 12:16 PM

ChrisCarter

Senior User

Joined: Oct 2010

Posts: 377

Likes: 0

From: Henderson, KY

Test a few of them and if what you get is the same readings on all but one or two then you'd have some bad coils...

Heres an article on the (COP's) hope this helps Part 1 - Testing the FORD Coil-on-Plug (COP) Coils

Jan 9, 2011 | 04:04 PM

DOC1KOC1

Thread Starter

New User

Joined: Mar 2006

Posts: 21

Likes: 0

problem fixed

Just a follow-up... I tested a new one and it was .6 ohms. So I tested the reast and they all tested fine. I did find 1 with the clip broken and wasn't very tight. I cable tied it and all is well.... I just wonder why they don't list what the reading should be in the repair manuals.....
DOC

Jan 10, 2011 | 10:03 AM

Djack04F150XL

Senior User

Joined: Aug 2008

Posts: 298

Likes: 0

From: Vicksburg, MS

With many miles on the truck I would suggest changing to a set #140033-8 of Accel COPs. Summit has them for around $270 + handling fee for the set. I put the 7989 Champion plugs and the Accel COPs in mine @ 71,000 with no problems since. I have over 31k on them. I noticed you had an '05 which has had problems with the injectors sticking. You should check that out also. They usually flood a cylinder and can ruin the cats in some cases. If you change your plugs have a Lisle tool set on hand and follow the TSB. Let the plugs soak overnight if possible. I broke 7 when I changed mine. Patience is a must on this engines.

Jan 10, 2011 | 10:14 AM

8UP

Junior User

Joined: Oct 2007

Posts: 54

Likes: 0

From: Amelia Ohio

I would replace your plugs first.

Mar 20, 2013 | 06:10 PM

shawngilmore1967

New User

Joined: Mar 2013

Posts: 1

Likes: 0

Here's the deal with plugs and coils on these trucks. I ran Seafoam through my fuel and had a fuel injection cleaning done to my truck prior to replacing the plugs. When replacing the plugs, do no use a ratchet to loosen (until they are loose), use a small breaker bar (gives you more control of torque). Gently try to tighten and then gently try to loosen, then continue to work the plug, do not force. To make things easier remove the PCV line on the right side of the engine and unbolt your ECM to gain better access to the back two plugs on the left. Testing the coils are simple, place both leads on the two prongs, they should ohm between 5,000 to 6,000ohms, higher than 6,000 or lower than 5,000 is a bad coil. By the way, I broke zero plugs.

Mar 22, 2013 | 06:16 PM

Infantryman1991

Junior User

Joined: Nov 2012

Posts: 71

Likes: 0

i keep getting a cylider 2 misfire. i replaced the coil and that didnt work. should i assume its the plug. if so would it hurt anything if i just replace one? im low on cash at the moment dont have enough for all 8 right now.