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Driving home this evening, all seems good, then I turn a corner and went to accelerate, and the car didn't seem to like that, seemed to be running on 3 cylinders!

So I pull over into a handily placed Repco carpark, poke around, plug wires seem ok, car runs just as badly with the intake pipe disconnected so it's not blocked.

So I go into Repco and buy some new spark plugs, put them in, no effect

At the moment I suspect plug wires, and tomorrow I'll put a new set in to see if it helps...

yeh sparkplug leads. it's not that unusual really.

Just had a lightbulb moment, so I headed down to the car this morning, and it started fine, which leads me to believe it's temperature related.

The NB8B has coil on plug ignition, and hence only 2 ignitors / coils, and I think one or both of these is not handling the heat...

So today I'll see if Mazda has a new set (or if it will be an 8 week wait like every other part on the car)

These things...



http://www.mx5parts.co.uk/product_info. ... ts_id/1078

Try swapping them from another car first caff - they're bloody expensive if you don't need them. You're welcome to try mine if you can get up here to get em...

Some knowledgeable people have suggested the CAS may be the problem, so I poured some water gently on (what I think is) the CAS and the car seemed to idle slightly smoother for a few seconds, so that may be the culprit.

If that doesn't work I might make the trek up to your place John, thanks for the offer!

Caffeine wrote:Some knowledgeable people have suggested the CAS may be the problem, so I poured some water gently on (what I think is) the CAS and the car seemed to idle slightly smoother for a few seconds, so that may be the culprit.

If that doesn't work I might make the trek up to your place John, thanks for the offer!

Hrmmm, it seems there are two cam angle sensors, and 1 crank angle sensor, which do I order I wonder...

One is cam angle sensor the other a crank angle sensor. Niether are in the piccies. The one your after fits on the top rear of the valve cover, the other attaches to the lower front part of the engine. The one you are after is the cheaper one. I have 2 spare coils, a cam and crank angle sensor if you'd like to borrow them?

I also have two spare coil over plugs, mazda wanted like $370 each

At the moment the cam angle sensor is out of stock at mx5 parts uk.

Does anyone know the torqe spcs of the bolt that holds down the cam angle sensor???
If feels feels like the bolt is very hard to turn, I just dont want to break anything...

Garry wrote:One is cam angle sensor the other a crank angle sensor. Niether are in the piccies. The one your after fits on the top rear of the valve cover, the other attaches to the lower front part of the engine. The one you are after is the cheaper one. I have 2 spare coils, a cam and crank angle sensor if you'd like to borrow them?

That would be great Garry! I don't want to go an spend hundreds of dollars on stuff that isn't broken to find out which part is!

I just (slowly) poured 500ml of iced water over the one on the top of the valve cover, didn't appear to help. Doesn't mean it's not the bad guy I guess.

May I come and pick up the parts tonight?

Ok, 1/2 fixed!

Thanks to Garry, I was able to swap in plug leads, coil packs and cam angle sensor (in that order)

The cam angle sensor seemed to make a slight improvement, and after about 5km the idle is back to normal.

The car still feels like it's struggling to breath, and sounds like it has a pod filter on it. So tomorrow I'll take off the intake and see if there's any blockages etc

So some progress, once I get all the problems nailed I'll swap my bits back in, buy the replacement for the offending part, and give Garry's parts back to him

Any solution Caff? Or are you still on the pushie and wondering why?

I'm taking the car in to top tune next week, I've run out of ideas!

Did you replace the leads?
They can be heated affected... work ok when cold then play up as the engine heats them up.

Checked for an induction leak?