My sons 2000 land rover discovery 2 (4.0L) has developed a hard miss when it is running at approx 35-40 mph. doesn't happen all the time but
seems to be on warmer days when it is occuring. He replaced the fuse box in the dash in cabin last fall due to failing board connections on the old one
causing fan problems. when it exhibits the behaviour, it is a solid jolt like the engine just stops firing for a split second and then continues.

No codes being thrown. (ie: misfires).

any ideas on what the cause may be here?

 

Plug wires most likely. You might be able to see micro spark leakage at night with the hood open but given it is load dependent maybe not. Inspect the wires for arcing. Once you have a code you can swap the plugs around to rule those out (they almost never go bad - not never, but almost never).

 

we did new bosch plugs on it last fall. but not coil packs/plug wires. He has both. Next visit, we'll tackle that job. thx for responding.

 

did the coil packs and plug wires over the holidays. happy to report that this resolved the problem 100%. one of the plug wires had separated at the plug and
wasn't making contact at all.

what a ROYAL PITA job that was getting to the coil packs.

Surely there is a seller offering great deals on coil relocation kits ?

 

LOL. https://extinctmotorsports.com/land-...elocation-kit/

 

I knew you were lurking out there!

will check it out when I do my rig. No misses yet.