Dash Light Lag Accompanied By Exhaust Sputter When Starting LC100

[Les Summer]

OH!

BTW: It's easier to replace PCV grommet, while head cover off. If it's old and hard.

fought that battle, when it was brittle and hard. it was a tiny miracle I got it all out of there.

 

[Les Summer]

I get Coils & Spark plugs, form Denso or Toyota Denso. I buy from only Denso distributors or Toyota. There is so much China bootleg junk out there.

Glade to hear zero rust.

Sure wouldn't hurt to do fuel pressure and fuel Injector leak down tests. Typically with excessive leak down. The complaint is long crank to start.

I know we did the dozens on coils a couple years ago, so I'm back here with an update. And... for a little help. @Lochness I'm looping you in here since I owe it to you, since you asked me about a year ago how the Hitachi coils were doing. Today, I can't tell you with confidence they are doing good.
I have approximately 293,500k miles on my 2000 LC100 and I installed the Hitachi coil set around 263k miles. I now have 2 Denso's on my truck, and will slowly replace all 8 with Denso's. I bought 1 from NAPA and 1 from Advanced Auto in the last day or so. Here is my story.

It started with me doing a 30k routine check of my spark plug torque. not a single issue before this. I've been dealing with this issue for about a week, and after about a week of trouble shooting I believe I disturbed a coil pack that was on the verge of failure when I was working on checking my plug torque.

I have been getting CEL accompanied by VSC Trac VSC OFF warning light on the dash and the following codes:
Accompanied by the C1201 code for my Land Cruiser were the following codes listed below, and I will explain each according to the 2000 Toyota LC100 FSM Engine Diagnostics Section:
P1330 No. 7 ignition coil with open or short in either IGF1 or IGT7 (coil)
P1325 No. 6 ignition coil with open or short in either IGF1 or IGT6 (coil)
P1300 No. 1 ignition coil with open or short in either IGF1 or IGT1 (coil)
This would lead me to investigate IGF1, since I am sure I did not have 3 newer coils fail me at once. I likely have an open short in IGF1.

I later learned from the FSM the culprit was likely coming from a plug connector. Cleaned all connectors, and the same dash lights and same codes returned after 20 miles of driving. Next I checked 7, 6, and 1 plugs. all plugs are fine and torqued to spec. next I purchased an ignition coil tester, and all coils tested to be working indicated by blinking light.

I then checked power at the ignition #1 connector with ignition in on position (vehicle NOT started) and I wiggled the wire while holding a test light to the positive wire, and the light tone stayed true without interruption, so I don't think power is being interrupted there. I have not done this test on any other connectors yet, but I plan to as my next trouble shoot step if needed.

What really thwarted me is my initial belief that my coils just could not possibly be bad, and this problem simply had something to do with wiring, torque, or plug connectors. I also worried if maybe I bumped my plug gap off by mishandling, but again, I did a good visual inspection of the plugs and they are good. I never considered I might have a weak coil on the verge of death, and just happen to die on me while I was uninstalling them to do this job.

A quick note on copper wire, because I've given the idea of a broken wire much though. Copper wire does not expire for 100 years. However, like any wire, enough bending back and forth will lead to breakages. I don't think at this point I'm dealing with a wire breakage after only unplugging some connectors. It's probably these dang Hitachi coils @2001LC warned me about from the beginning. I say probably, because I'm not sure if I cured this problem yet.

I still have crank shaft and cam shaft position sensors on the back of my mind, but that's way off down another rabbit hole I am staying away from at this time.

SO today I swapped #6 and #4 coil to find P1325 disappeared and P1315 appeared. I'm being mindful that a single bad coil can cause misfire codes which can indicate other coils appearing to be faulty, so there are no guarantees. I decided to replace #4 and #6 ignition coils with DENSO's and I brought the two Hitachi's inside for some testing with the multimeter. I replaced #4 and #6 since they are a pain to get to since you have to remove the air intake. I also destroyed one of the Hitachi's by closing my hood on it, Doh!! hood is ok though.

I tested ohm readings on the Hitachi coil by touching my multimeter to pins 1 and 4, which are in order of left to right if you are looking at an installed coil. I compared my ohm readings to my OG DENSO coil I had laying around. I kinda sorta mixed up the coil packs, so I'm not sure which one is the one I thought I had on cylinder #6 and #4, but both had readings in ohms lower than the old 260k+ OG DENSO. I had 17.0 on one Hitachi coil and 18.4 on another, while my DENSO consistently ready 21.3 ohms. NO IDEA if switching out the coils has fixed this issue. I have found the CEL and VSC Trac and VSC OFF lights return anywhere between 20 and 100 miles of driving.

For giggles I weighed the old DENSO coil and compared to the weight of the Hitachi's. The Hitachi come in at approximately 7.2 ounces, while the DENSO comes in at 7.7. So definitely a different build. I'll be back with any updates to report if the coil swap solved the issue, or there is something else going on.

 

[Les Summer]

so my guess is the coil weight does not mean much. I just restocked my parts supply with another new DENSO coil, for when my next Hitachi poops out on me, and it weighs the same 7.2 ounces as the Hitachi coil. The only real way of knowing the differences between the coils would be to do a cut, and I'm not that unconvinced there is a difference, so I'll leave that mess for somebody else's garage.

I have spent about 80 miles of driving now with my 2 DENSO replacements installed, and the fear of another CEL is starting to subside. I have a trip to my mother's soon that will be about 300 miles of driving. I will report back after that to say with 95% confidence if I don't get a CEL after that, I think I'm fixed.

 

[Les Summer]

Yeah, I think it was the coils man I think I’m good. I’m another 150 miles in of all kinds of driving and no more dash lights. I do believe it was a bad coil.

 

[Les Summer]

changed out all coils to Denso. already notice easier startup, and better mpg by a lot! over and out.

 

[2001LC]

Great!
The market has been saturated with bootleg from China. Anytime someone, offers a deal, much below $60, 80% chance junk, below $50, 99.99% junk.

 

[Les Summer]

Great!
The market has been saturated with bootleg from China. Anytime some offers a deal, much below $60, 80% chance junk, below $50, 99.99% junk.

I got them 7 of 8 from NAPA $87.99 and got 1 from AdvancedAuto, about same price. I paid under $50 for the Hitachi's off Rock Auto. I notice the connectors seated very snug with the DENSO compared to Hitachi.

I see rock auto also has them around the same price, and Autozone does too. The dealer wanted 220 around here, and I could not afford that. I'd of been willing to pay 20 or 30 more just to get them from the dealer, but not that much.

The NAPA guys were pretty proud to sell them to me. One of the guys was praising the DENSO's as we spoke at the counter. He seemed to believe they were better than all the rest..