TJ won't start after replacing coil

benjishack

New Member
Original poster
Joined
Feb 17, 2022
Messages
12
Location
united kingdom
Hi All.
So I had to replace the coil on my TJ 4.0 .
So I got hold of a Lucas replacement coil and it fitted/plugged in perfectly.
The jeep now wont start and sounds like its misfiring all over the place and I'm fecking stumped as to WTAF IS GOING ON
 
If I had to guess it would be a defective coil. Try putting the old one back in? Why did you have to replace it in the first place?
 
How long has the engine been misfiring OR did the misfiring just start recently?
Does the engine misfire while idling OR when driven OR both?
How bad is the misfiring?
Have you removed the spark plugs to determine their condition and figure out which cylinder is misfiring?
In a dark garage or outside at night; check the spark plug wires for arcing to the head or between the wires.
 
Last edited:
Throwing codes? P300 through 6? Or one in particular?

Have you inspected the wiring harness?

Most of mine went away replacing the cap and rotor with an Accel on my 97.

What plugs are you running?

-Mac
 
So I put the old coil back in and started the tj up and it ran perfectly and had a drive round town with no problems. Left it for an hour and tried it again but now it's back to running but very lumpy and exhaust doesnt smell right.
So it seems the old coil is failing...
 
I'm not aware that being an issue on the TJs.

You may just have picked up a bad coil.

I'm not sure what's available over there, but the MOPAR or Blue Streak by Standard Ignition are the only ones I would consider putting on it over here.

The Blue Streak is made in Poland, so you might be able to find it there.
 
You had a TR6 like me so I'm sure your familiar with Lucas not caring.
Lucas.... Prince of Darkness. And does everyone know why the Brits drink their beer at room temperature? Because they have Lucas refrigerators. :ROFLMAO:

By the way, my TR-6 never had a single problem. It, almost surprisingly based on Lucas's reputation, was a beautiful problem-free car.
 
  • Like
Reactions: TJ4Jim
Lucas.... Prince of Darkness. And does everyone know why the Brits drink their beer at room temperature? Because they have Lucas refrigerators. :ROFLMAO:

By the way, my TR-6 never had a single problem. It, almost surprisingly based on Lucas's reputation, was a beautiful problem-free car.
After swapping in the Pertronics ignition system my 6 was a good runner.