MG ZR 1.6 5 DR

[gert123456789]

good day all

i just bought an Mg  ZR 1.6 5dr and it was idling fine and all of an sudden it started idling almost 2000rpm 

i have one the pedal reset on ecu but still not getting results 

any more advice i can try

[nickwheeler]

Nov 29, 2023 5:51:39 GMT gert123456789 said:

good day all

i just bought an Mg  ZR 1.6 5dr and it was idling fine and all of an sudden it started idling almost 2000rpm 

i have one the pedal reset on ecu but still not getting results 

any more advice i can try

The only way it can idle at that speed is if it's getting extra air from somewhere. So first  ensure that the throttle spindle is actually closing. Then go over the entire intake system from the throttle body to the engine, checking for split hoses, cracked fittings, faulty idle motor or a damaged inlet manifold.

[stealthstylz]

They used to have a problem with the throttle plate sticking, but that was usually when the engine was revved it would hang open and cause a high idle.

[homersimpson]

Dec 1, 2023 21:40:45 GMT stealthstylz said:

They used to have a problem with the throttle plate sticking, but that was usually when the engine was revved it would hang open and cause a high idle.

I recall something about this, some of them had plastic throttle bodies that did this (this might have been the earlier rover 200 series though?).

I would suggest the throttle body as the most likely culprit followed by the idle speed control valve.  If you can get the air cleaner off and look down the throttle body with it running you should be able to see whether the throttle body (or the linkage to it) is the culprit.

[automax]

If its an early one with the plastic throttle body swap it out to the later alloy type. The body either distorts causing the butterfly to drag or the shaft gums up causing it to stick. Other culprits will be IIAC (often cured by a good flush out with carb cleaner), stepper motor on the throttle body (again, just swap to alloy) or coolant temp sensor.