Ignition coil testing?

2000 tundra 4.7 v8 4wd 75,000 miles

Engine running rough, seems to be misfire
Check engine light on but OBD reader/port won’t connect — reader does work on other vehicles — seems no power at obd port — still need to confirm

Any way to check the coils individually? Maybe pull connector while running to find bad coil?

Any other way to find a bad/ not firing coil without OBD access?

 

yes pull the coil connectors one at a time and see if it makes it worse or maybe the one you pull there may be no change which would indicate that is the bad one. Your 2000 with only 75k miles.? nice.

may need a maf and throotle body cleaning to

 

Found the fault in the OBD — no power to port 16 — this was due to previous owner running a new wire directly to the fuse box from the OBD port which I disconnected months ago thinking it was power to a radar detector

Code was p0301 — misfire cylinder 1

pulled the coil and checked the plug, it was wet with fuel and light brown — electrode extremely worn

I guess tomorrow I’ll swap that coil around to another cylinder and see if my misfire moves with it

What plugs do these things like?

 

Where are you located? Just buy a new Denso coil at Rock Auto for $50

 

Bought it back around June of 2021 with 68,000 from original owner who was a friends father — he had it listed on facebook marketplace — when I reached out the listing was gone, turns out friend had brought it in for the frame to be checked on the recall — and Toyota was replacing it — told him not to re-list it, just call me when it was done and I’ll come get it — $7,000

I did do a throttle body cleaning when I got it along with timing belt, water pump, radiator, belt and hoses — ran like a champ till this morning on my way to work

 

yea but trying not to be a parts changer and actually diagnose the problem 1st

 

Isn't there a fuse for the obd? you may also need to pull the panel around the obd2 port and check for wiring damage on your power wire and repair it... if you believe the ECU may have been damaged there are services that may be able to help out on a ECU rebuild or a new ECU, since a bad ECU will have you chasing and replacing unnecessary parts..

 

Yes there is a fuse for obd — 7.5 amp and 1st thing I checked

No reason to think ecu is damaged — will move coil tonight to another cylinder, hopefully my miss moves too

 

hopefully its just in need of new spark plugs iirc they are br6eya ngk $3 a plug

 

You want iridium 70k mile plugs. @Heavyopp read this thread: https://www.tundras.com/threads/miles-on-spark-plugs.97543/

Which one you pick depends on your year/engine IIRC. Mine takes different than yours I believe, but I can't remember.

Also, if you have Advance Auto parts near you, take 25% off on a local pickup, look here: https://www.tundras.com/threads/1st-gen-lunch-table-general-discussion.60450/page-779#post-2495117 and if that code doesn't work anymore, I think DEC20 will take $20 off your order if you can get it up to $100 by tossing in oil change stuff, or whatever else.

 

That's a great deal, congrats!

 

Moved coil to cylinder 4 — fault code/miss moved along with the coil — time to order an ignition coil — probably order a spare as well

also pulled #4 spark plug just to get a look — denso copper electrode type and firing, white brown in color but extremely worn electrode — time for a set, guess I’ll go iridium as suggested above

Rock auto is my go to when I have the time to wait for delivery. I will check advance for the plugs but gonna pay shipping from rock anyway, might as well get the plugs too

 

Don't forget, you get same-day pickup at your local dealership (if one nearby) through https://parts.toyota.com

OEM is always best bet on this one, but do what your budget allows.

Whatever you do, DO NOT order from scAmazon or fleaBay due to massive counterfeit problems, if you're not already hip to that whole mess.

Oh, and there's a brand - is it Bosch? - that sells the exact same OEM (Denso) coils with the Denso name ground off, and I think they're 20% cheaper.

Advance Auto Parts always has 15% off coupons floating around, sometimes as much as 25%, order online and pickup in store 1hr later.

 

I’ll OEM when it makes sense — here it didn’t — why would I pay 100% more for the exact denso coil to say Toyota on it

Advance had the plugs, have 4 or 5 stores all within 15 minutes, but plugs where almost double the price of rock auto, even with shipping

I’m in no rush, have plenty of Jeeps around to get me where I need to be

Rock auto is usually 2 days delivery

 

They were quick to get out my last part ordered a couple months back. I hadn't ordered from them in 10+ years 'til recently. Last time was ordering a ton of Moog suspension parts for one of my old pre-kids project trucks. They've gotten a hell of a lot better with their out-the-door and ship costs.

 

Already have a tracking number...

 

the copper bkr6eya plugs has the proper gapping where the other more expensive metal ones do not sure they’ll work and last longer tho glad you have worked it out

 

Pic of offending coil? Any noticeable degradation?

 

nothing noticeable but I’ll be sure to take a pic of the old and new coils next to each other in a few days

 

hows about a ohms test to check the old coil spec??

thing is some of these new aftermarket coils work but they don’t test in spec like new denso and toyota spec per fsm just sayin.. glad you are worked through the problem and at least reportIng back you seem like a good problem solver.

 

As far as I know I still bought OEM coil just not through Toyota — Toyota doesn’t make the ignition coils Denso does

I can certainly check ohms but how? What terminals? I think there are 4 wires up top on the wire connector.

 

unsure its around here somewhere and in the fsm your good2go if denso..

 

Anyone know what the spark plug torque is supposed to be, mine are what I would consider loose

normally I wouldn’t bother with a torque, just snug them up as normal for a spark plug but might as well see what the spec issupposed to be

I do see 66 in lbs for the coil bolts


Forgot to mention, parts are here

 

double check but iirc they are 13ftlbs

trouble is if you already crushed the plug washer then torque wont matter so much. best to just hand snug every 3-5k miles as they tend to come loose regarless..

 

Nope, haven’t installed the new plugs yet — just the couple I checked during the week where “loose”

going out to play with the truck tonight

 

Heresy

 

Certainly not identical — new on left

 

looks legit the 4.7l landcruzer guys swear buy them..

 

Turns out someone snuck an aftermarket coil in there — cylinder 5 — I’ll keep it as a spare, it was working but I installed the “spare” denso I bought

 

And 8 worn plugs...