i have a mazda 121 zetec s (Fiesta mk4) 1999- 1.25 - petrol - and i am experiencing an issue with my engine.

if i am stationary everything is normal, revs are at 1000 - 1100 rpm but once i am moving even 1mph my engine wants to sit at a minimum of 2500rpm like it has cruise control it will go lower but i have to hold the break pedal.

this only happens when im moving. this is an issue for me as i have completely lost e-breaking and when i put the clutch pedal down just before coming to a stop my revs shoot up to 3000rpm.

i have checked and cleaned the ICV, the MAS, i have reset the ECU. the break fluid, oil and coolant is all topped up and everything else works fine. i even checked the power steering sensor just to be sure that had nothing to do with it.

im pretty handy with cars but no even the mechanics can sort this issue. any thoughts would be appreciated.

 

Try looking for a air leak from the inlet manifold as that will cause the revs to rise.

 

it doesn't rev high when its stationary though. do you think this could still be it. i will check tomorrow

 

check the throttle position sensor its quite common on those