Mystery Misfire

  1. My model of MX-5 is: __Mk 3 NC 2.0 Sport
  2. I’m based near: __ Nottingham
  3. I’m looking for technical help or recommendations on: __ misfire and components

Still can’t get rid of the misfire and erratic idling. I’ve read quite a few posts and it seems there’s loads of possible causes.

So far:

  • I’ve had the plugs and coil packs replaced,
  • put a new MAF Filter on
  • had the engine de-carboned
  • used injector cleaner
  • had it dyno’d and compression tested (slightly low on cylinder 3)
  • swore at it.

It seems to be getting worse on tick-over (see video) and at low revs under load.

Does anyone know what the sensor things are in the photo please? There two at the top are almost identical, there’s a red one (and hidden blue one) below.

Answers on a post card please.

Photo - https://1drv.ms/u/s!Aocje4R__8gTgpcrTDy5AB1Gdca7KQ?e=LcQdTD
Video engine - https://youtu.be/iPLR87f7r44
Video exhaust - https://youtu.be/D9WIILzHWkw

Advice welcome.

The COP plugs and wires are known to give that kind of fault by breaking, i’d start there.

1 Like

The pipe he red collar is the high pressure fuel feed hose. The other 2 components are solenoid valves for the variable tumble control and variable air intake control. The blue hose is part of the evaporative system.

Woohoo, cheers Roadster.