MK1 mx5 revs bouncing at 2k

Technical Area Engine, Transmission, Exhaust etc
1
  1. My model of MX-5 is: __ MK1 mx5
  2. I’m based near: __ Nottingham
  3. I’m looking for technical help or recommendations on: __

Hi guys I’ve recently repaired the thermostat t fitting from the common leak. whilst running the car up to temperature to ensure there’s no leaks and the new thermostat is working etc, I noticed that when I rev the car slowly and hold the revs at around 2k-2.2k they then bounce down to 1.5k and then back up. If I give it a bit more throttle this then makes it bounce up quicker. if I give it substantially more throttle it can power past this ‘limit’.

The car is up to temperature on the drive I’m yet to do a road test.

Any advice will be much appreciated.

2

I assume that the fault wasn’t present before you did the work? First thing to check is everything that you disturbed during the thermostat repair.

3

I cant say for sure if it was there before hand. I dont recall ever really holding revs in neutral like that to test. doing a road test it has the same driving oddity as before where you loose out on power which would make sense to be the same. So sounds like it may have been there before.