Pandora's Box of Ignition Coils

So, I decided to check ignition coils and spark plugs (one at a time) this weekend and now the truck runs like crap, rough idle and noticeable loss of power with check engine light on. It was running perfectly fine before but I guess I opened Pandora's box by messing with em. haha

Almost all coil body's were dirty and cracked but the plugs looked good. Not sure what I did to cause it but I've got an order in for new Denso coils and plugs. Another $500 invested in this beast. Hopefully that'll get it back to normal.

 

I had the same issue, Denso plugs fixed it right up. Keep an old plug on hand in the truck for emergency’s.

 

I'm going to replace my plugs this weekend. I hope it doesn't turn into a mess. They have 150,000 miles (oops lol) on them, so I'm expecting disappointment.

 

You can replace them one at a time, or one side of the engine at a time just incase.

 

I am almost more concerned about breaking a plug off after 21 years and 150k. I feel like I have to do it now before I detonate a plug. I'll really have problems then.

 

I did mine at 163k no issue. Good luck,

 

Squirt a little penetrating oil down each tube and let it marinate for a few. Then when removing the plugs if there is resistance, slowly work them out by loosening, then rotating back toward tight, then loosen some more, then back toward tight and "walk" them out slowly. The threads get crusty and buildup in the channels locks them up. The back and forth helps to keep it from blocking them completely. Good luck!!

 

Most of my plugs came out like they were finger tight. No clue how long they had been in there, or who changed em. And i meant to check the new ones…and still might.

 

any rec's on cleaning the sleeves the coils/plug slide into? Some were pretty nasty covered in brown soot and stuff.

I think I read somewhere on here to use a lint-free rag with some cleaning solution but can't remember what.

 

I did the plugs in my son's girlfriends Tacoma, they were original and they all felt finger tight. My son should have tackled that job, but don't get me started.

 

I think it's acetone.

 

$55 Denso 6731303 Ignition Coil , Gray

https://www.amazon.com/Denso-6731303-Ignition-Coil/dp/B002Y37M0W#customerReviews

 

Never Trust Amazing with having genuine electrical items. They have fakes all the time.

Use Rock Auto

 

When I did plugs on my 2nd gen I just took the coil packs off and then used compressed air to blow out any crud in the sockets before I took the plugs out and opened the cylinder to the crap falling in. Did one at a time, no problems. Also, I second @SouthWestGA , I wouldn't trust Amazon for genuine electrical items or plugs. I usually go Rock Auto for that.

 

That is me. I stabbed a transmission for a clutch job for my girlfriend when I was his age. He can't do 6 plugs. I hope he got no reciprocity for my work.

 

review look good some have years of feedback Denso store quality Hitachi to many hear doubt but still mangle there own trucks but blame part

 

Reading this made me think I was having a stroke for a minute. Re-read 3x, panicked, then asked someone else to read it. Same result. *phew*

 

that comment i made was right after coming out of a coma induced by one of your endless brain numbing novels.?

those reviews look good unless the bad ones are shadow banned??

everyone says rockauto but ironman bulild guy has faulty head gaskets from them with only 3k miles??.

 

It depends on what brand you get. I also got centric shoes for the rear that were crap. I only get good stuff now.

 

Finished mine this morning. Late start and I really did not want to work on my truck today. All plugs were down to the porcelain, so I am glad I did it. Had to walk the rear plugs out, they were grabbing the threads, but got them out with no damage. I don't like using anti-seize on plugs, but I ended up using a little. Fired up and ran great, the coils looked brand new beneath the valve covers. 8 plugs and no problems, I'll take it!!!

 

Welp, I figured out why the truck ran like crap after checking the plugs……..see if you can find the problem. Hint: far left plug. Hahaha I mustve forgotten to plug the wiring in. Doh!

And I didn’t discover this until after ordering new coils/plugs and just before installing the 5 out of 8 new coils/plugs. At that point there was no turning back. Oh well, $500 for piece of mind and the truck runs great. 2nd and 3rd pics are what I pulled out

 

Been there. Was timing by brother-in-laws 327ci 67 Chevy short wide with a timing light. You take the #1 plug wire off and use it to trigger the timing light so you can see the timing marks on the harmonic balancer strobe like fashion. After unsuccessfully trying to time it with the light (marks were way off it seemed), I went old school and timed it by ear at idle which worked better. After finishing, the truck had a skip to it and ran a little rough. I could feel it in the seat. Turns out, I never hooked the #1 spark plug wire back up. Doh! Ran great after I reconnected it. I always try to remember to retrace my work at the end of a job so I don't leave tools in the engine bay, or stuff unplugged. It happens.

 

Over the years, I’ve had replaced 5 of mine. When the fail you get a horrendous shake and lack of power under load with only slightly rough idle. ECL may only come on under acceleration. OBD code can tell you which cylinder but can also find by pulling one connector at a time and noting which does not change the idle. Paid over $100 for the first one at FLAPS but then paid $50 each at RA