MG ZT 1.8 turbo rpm bounce

[Mike Farr]

Firstly I would like to say a big hello.

I have recently purchased my very first MG ZT. Its the 1.8t will get around to posting a picture eventually.

I have a few questions/concerns and would like to know if it the norm or something to worry about.

So firstly I have noticed when idle, no climate control turned on, lights off ect the rpm seems to bounce between 600 & 800 rpm. Its worth noting the fool before me was running it without an air filter and holes drilled in the box.

Secondly only when turning I sometimes get a bit of a boot rattle.

Any help would be appreciated, and in return I will gladly help out as and when I can.

Cheers

[danbmx_69]

my car allways did this on idle form when i have had it, few weeks ago i changed the lambda sensor and the spark plugs( due to emissions fail on MOT) and now subsequently the idle is as stedy as a rock :}

[pab]

It's very rare to see a 1.8T idle smoothly, there is a always a little fluctuation. The Stepper Motor on the Inlet could be the problem. This really needs to be fine tuned on a T4.

[marinabrian]

It's very rare to see a 1.8T idle smoothly, there is a always a little fluctuation. The Stepper Motor on the Inlet could be the problem. This really needs to be fine tuned on a T4.

Mine idles beautifully :p:

Probably needs the IACV setting up correctly, this is a T4 job, so have a word with Terry in Stourbridge ;)

Brian :D

[Mike Farr]

Well thanks for the replies guys hopefully I can get to the bottom of this and try and get one of this fine tune done. I suppose it cannot hurt to change the plugs and sensor so I will give that a go in the mean time.

[Mike Farr]

my car allways did this on idle form when i have had it, few weeks ago i changed the lambda sensor and the spark plugs( due to emissions fail on MOT) and now subsequently the idle is as stedy as a rock :}

Could this also be the reason tje car is drinking fuel like its going out of fashion? Even with a light foot?

[pab]

Could this also be the reason tje car is drinking fuel like its going out of fashion? Even with a light foot?
This could be down to a faulty coolant sensor, the ECU would fuel the car as if it's cold and perhaps would account for a fast idle.

The car really needs to be hooked up to a T4 to pinpoint the problem.

[stevestrat]

It's very rare to see a 1.8T idle smoothly, there is a always a little fluctuation. The Stepper Motor on the Inlet could be the problem. This really needs to be fine tuned on a T4.I have the 1.8T erratic idle, comes with the territory. It was improved by Brian and his magic box, discovered my stepper motor had never been adjusted!

[Mike Farr]

Would just like to say thanks you to all! rpm bounce is now solved, it wasin fact the stepper motor was set too low so it was almost stalling.

Also I had a run on diagnostic turns out my cousin has one. Big MG/Rover fanatic.

Oh just out of curiosity i will be going to Pride of Longbridge with my cousin, anyone from here?