Idle drops and either picks back up or cuts out

Technical Area Engine, Transmission, Exhaust etc
1
  1. My model of MX-5 is: MK2 1.8 Sport
  2. I’m based near: Wiltshire
  3. I’m looking for technical help or recommendations on:

Hi there, I’ve noticed since getting my MX5 a few weeks ago that If I leave it running/idling for a bit, it often drops to the point of almost cutting out and either jumps back up by itself with a little struggle or just stops completely.

Any obvious causes for this? I’m not mechanically minded so please excuse my ignorance. Hopefully we can narrow this down a bit

Thanks

Matt

2

Just to add the time it cut out completely, it didn’t really like turning back on! It did in the end but wasnt great

Drives fine, no issues otherwise. Hopefully a simple solution, if there is such a thing :wink:

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Update following advice on Reddit

Checked the MAF sensor, looked clean visually but gave it a clean and spray with electrical cleaning spray. while it was off I soaked the Air filter in degreaser. 2 buckets of filth came from that. Airline to spray it all out and dry it off, sprayed with K&N stuff before putting it all back together.

Im sure it’s resolved the issue and feels 100xs better pulling away in the lower rpm range and so far from brief testing, the droop I was getting has gone.

Had to then clear the engine light that came on as a result of messing with the sensor but all seems good now.

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Have you checked for fault codes and any water under the carpet in the passenger foot well.
M-m

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I had exactly the same fault with a 1.6 mk2.5 and it was air flow meter

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Yeah! I’m glad I tried it. I can’t say if it was that or the air filter ultimately, as I did both at the same time but the filter made 2 buckets of degreaser absolutely filthy.

Idles perfectly now. Originally when I first started driving it, I found it a bit bumpy when pulling away at lower revs, this has resolved that too. Clearly wasn’t getting good air flow or something in that area.

7

Thanks for the responses here. I have exactly the same problem currently on my 2005 NBFL 1.8 Arctic. My Mazda dealers cant find the problem so I will ask them if they have checked these two points. Apparently nothing comes up on the diagnostics check but I guess back then it wasn’t a very sophisticated system.