Had to replace battery today - hadn't started the Jag for a couple of weeks, and I've not driven her much

I switched from a Group 47 battery to a Group 49. The 47 is the 10" long battery rated at 600 CCA/ 725 CA.

the 49 is the 14" version rated at 800 CCA, 1050 CA.

2-3 weeks ago, I drove her (after sitting a month) and she threw o2 sensor codes. I reset the codes and she sat until today when I replaced the battery.

Inspection guy said I have to drive her 60 miles (after resetting codes) then come back to get inspected.

I drove her about 50 miles and then, all of a sudden, all dash components flickered

She runs great and no codes are set, but the dash components are wonky

Any ideas?

Here's a video of what's happening

 

Common issue.

You have an ignition coil failing.

*Sometimes* you can identify which coil by removing the coil cover and running the engine in a dark garage. If one of the coils is flashing thru the epoxy top, that's the bad one.

Lacking that, buy one new coil and try it each position.

Make sure to get a true OEM, Made-in-Japan coil


Cheers
DD

 

Could be the ignition coil(s). Lots of info on the subject.

I realize I wasted time loading all the TSBs into the large file area?????
Nobody reads them.

bob

 

Motorcarman, I read the info and I am sure a lot of other people appreciate your efforts. Thankyou.

 

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thanks Doug and Bob!

I feel bad I did not do enough of a search. I've been here a long time and have contributed myself. I've also been a member of many other car and motorcycle forums, so not unfamiliar with what I should do, but obviously did not today

So, tomorrow I will check the coils.

And replace the inter-carb fuel lines on the '93 Hurricane, replace oil sending unit on the '64 Buick, so I can get all the vehicles to the new house at end of month. Four cars and four bikes are obviously overwhelming me

Anyway , I appreciate the swift response, so thanks again ! I will provide feedback when done

 

Christmas Tree Syndrome,just in time for the holidays! Seems to be one of the easy things to diagnose on these cars since you don't even need to use a code reader. Thankfully it's an easy and quick fix.

 

Yes, it seems the Jag is celebrating the season with its own version of Xmas lighting.

Checked coils - all are fine. It's also not related to the two TSBs posted in this thread.

It appears to be "mileage" or "time car is running" related. All is fine until I've driven 10-15 miles. The second time I drove it was to put the remaining 12-15 miles needed to get to "60 miles beyond the last time I reset codes".

So the dash again did flicker, but since no codes are thrown, I drove her to inspection station. It took a couple of tries for his equipment to sync with the Jag. I noticed the same issue with my code scanner - it took two tries to sync up.

Anyway, she did finally pass inspection.

I wonder if it's related to the new battery I installed. I know these cars are fickle related to voltages. This is a Group 49 (with higher CCA and CA) than the Group 47 I've always used. Or maybe it's a coincidence.

 

I had the same issue. There were no codes thrown but the lights would start flickering after about 10-15 minutes of driving. After replacing my coils the issue went away. The engine ran smooth even before the coil change so it may have become somewhat less noticeable that there was a bad coil at a higher rpm. I'm also running the larger capacity battery figuring it wouldn't hurt having the extra power as a backup. I'm sure changing your coils will solve your problem.