Ignition Coils
 

I read some old threads regarding ignition coils and I was wondering what the update is. That is are any of the off-brand coils lasting more than a year? Can you still get the Lucas coils that came from Japan? If yes, then how much?
I have 140,000 miles on my car and I suspect that the coils are original. The car drives very nicely but does not have the same power as my 95 xjs so I was wondering if this could be because of the coils? I have 40,000 miles on the plugs and will look at them tomorrow.
Thanks!

I have been using QYL brand of coils for close to 2 years now. You can buy a 6 pack of them on Amazon for around $80.00. They are made in China and so far no problems. The Japanese coils are still available from one of the forum sponsors and are around $100.00 each.

Hi jomo,

At 40,000 miles, it's probably time for new plugs. Before you worry about your coils, I would recommend you do a basic tune-up: New Champion RC12YC plugs, air filter, fuel filter, clean the gunk out of the air intake plumbing and crankcase breather hoses, clean the engine bay ground points, including the engine ground strap, clean your Crankshaft Position Sensor (CKPS), adjust your throttle cable, and check your drive belts. Consider changing your coolant thermostat if it's been awhile.

I can't recall whether Live Data can be viewed with a scan tool on the '96 X300, but if so, you might check your Short-Term and Long-Term Fuel Trims for signs of lean or rich running, and check the various Engine Management System sensor signals for plausibility. For example, if the Engine Coolant Temperature Sensor fails at a resistance the Engine Control Module interprets as "cold," the ECM will continue to apply cold-start fuel enrichment even after the engine has reached full operating temperature. Likewise if the coolant thermostat is stuck open. Intake air leaks or problems with the Idle Air Control Valve can cause lean running.

Cheers,

Don

It can.

In this case though, sluggish car will most likely mean TPS out of adjustment due to stretched out linkage. Mine was showing 4.2V at full open throttle when it should be showing as close to 5V as possible. At 4.2V at WOT it felt quite sluggish, when I re-adjusted it, it felt like I got an extra cylinder :)

Re-adjusted? How?

I assume what katar83 meant by adjusting the "stretched out linkage" was adjusting the throttle cable, as I mentioned in post #3.

Here is my update. I changed the plugs and got decent improvement. I cleaned the throttle body but it was actually very clean. The air filter is fine (always!). I also cleaned the gunk out of the air intake plumbing and crankcase breather hoses which again was fairly clean. I am fighting right now to get the fuel filter off. It is not in the worst place but is a bit of a pain. I got one line off and will finish up tomorrow. I have a feeling that will make a big difference.I changed the thermostat when I got the car 40,000 miles ago.

I do have a couple of questions. Where is the Crankshaft Position Sensor on this car and how do I adjust the throttle cable (or even know if it needs adjustment)?

Thanks for your time!

Wow is that helpful! Thanks

It took a total of 90 minutes to get that fuel filter out. It was fun! The new filter was connected easily and the car drive better! Tomorrow I will clean the Crankshaft Position Sensor.
Thanks for everyone's help!

Hi,
Here is another update. I did everything that was suggested. Then my coolant temp sensor went bad and I changed that. The car still has a slight hesitation sometimes when I accelerate for just a fraction of a second. But this is my jaguar and that is unacceptable.
I think that I need coils, but first I will swap the coils from my 95 xjs and see if that corrects the problem. If it does, then I will purchase new QYL coils from Amazon.
For the record the car does drive better with the recent tune up
Thanks for your help

Final update. I swap the coils from my xjs and there was a decent improvement with no hesitation at all or should I say no misfire. Since the misfire went away I ordered the QYL coils from Amazon and they arrived today. I installed them and wow is there a huge difference. This car, with its new shocks (those rear shocks took a whole day to put in!), tires and recent tune-up drives amazing.
These cars are a blast to drive. Now it is time to get the convertible xjs ready!

Thanks for every ones help. It was not expensive and not hard to do a decent tune up on the car. BTW, the coils were $85 and has very nice reviews from XJ6 owners

Excellent! Please remember to come back here and update us if the coils begin misbehaving in the future. It may take 6 months, a year or longer...

Hi,
Here is a quick update on the QYL coils from Amazon.
It has been 6 month since I put them in and they are doing fine. I see no reason why they will not last much longer. And they only cost $80 for all 6!

We all do appreciate the update here. Please continue to keep up posted if/when something fails.

Very optimistic to hear!

Now if we can find an affordable TPS replacement....

Hi,
Here is a quick update on the QYL coils from Amazon.
It has been just over 1 year since I put them in and they are doing fine. I see no reason why they will not last much longer. And they only cost $80 for all 6!

At least in my car I call this experiment with the QYL coils a success!

You realize this thread is a year old right?

KIDDING. WOW! You actually came back to update everyone, props to you! People always forget that. Glad to hear that tune up really worked out well. And yeah, isn't that hilarious about ignition coil pricing? I'm sure the $200+ PER/coil products would be higher quality but you can literally buy TWELVE spare coils for the price of one of those in case one goes wrong. Plus if a coil goes bad it doesn't destroy an engine (like a bad oil filter or cam gear). I've been trying to avoid Amazon recently and was able to purchase a full set from 1AAuto.com for a little more $$$. I wonder if they are the same back-end manufacturer.

Keep us posted. I somehow doubt you'll have the same success. A lot of people have had bad experiences with all other coil manufacturers, not Made in Japan, until now. That's why this thread is so interesting. Most aftermarket coils seem to fail at about the 6 month point, and then a few survive to one year, however none of them had the longevity that Diamond provides.

This new brand, through Amazon, should have won this forum over. I know I would purchase them, if I needed coils.

At least 1AA has an interesting warranty. Perhaps if they fail, you will get free replacements?

Please keep us posted!

I installed a set of QYL coils nearly 3 years ago and they have not failed in any way after around 25000 miles
I decided to keep the original Lucas coils but have not needed to use them, They could be in the box for a while.

Hi I am new to this forum although I have been following on here for some years .., great site and lots of knowledgable members.
Hi, I am in the market for new coils .., specifically searching for the “more affordable” good quality options especially the QYL coils that many members having success with (some reporting that it lasts >3 years).
Only problem is that I cant seem to find any! I have looked everywhere!
Does anyone know where I can find and or who the manufacturing company in China is that makes these for Amazon? (Amazon has been out of stock for ages and don't know when and if they will get again). There is also no website on contact info for them.
5 of my 6 coils have one or more hairline cracks on them. They all seem to be the original Lucas “made in Japan” - Car has about 100 miles on the clock and I had her for about 10 plus years and have never changed the coils thus thinking its probably still the originals.
Any members had success with other brands of coils?
According to many “veteran” members Lucas aint Lucas anymore. Can find some Lucas locally but not sure if its worth it!? Or have the quality changed for the better over the last year or two?
Any feedback would be greatly appreciated.
Regards.