Uneven tickover NA 1.6

Technical Area Engine, Transmission, Exhaust etc
1
  1. My model of MX-5 is: _NA
  2. I’m based near: __Edinburgh
  3. I’m looking for technical help or recommendations on: uneven tickover.

the car was recently serviced and has just had a cambelt/ water pump change. It is an NA Eunos 1992 with 160,000 Km. It has been running fine until recently, and now after a cold start, the RPM fluctuates between 300 and 1100 before finally settling at 800 RPM when warmed up. Even then the car seems to be more prone to stalling.
Maybe the MAF sensor needs cleaning, but how do i do that? I have ordered new Bosch iridium spark plugs and new plug leads in case that is the problem.
Any ideas gratefully received.

2

The timing belt may have slipped a tooth when the crank pulley bolt was torqued up.

1 Like
3

I did one a bit back got exhaust cam slightly out , stalled when coming off revs

4

I sure hope it is not due to cambelt misalignment as that will involve dismantling the front of the engine again.
The uneven tick over only occurs for a minute or so after a cold start. After that it runs smoothly. I would have thought that a valve timing problem would be evident at all times. But thanks for the feedback, let’s see if there are any other possibilities.