Video showing over revving MGZT 190

[janker]

Hi Everybody
Im still trying to find out why my Car holds its revs up when coming upto a junction when cold,Ive tried different throttle control valve and new kit and cleaned many times,All linkage is free and working correctly.
I have tried another potentiometer also and no change.I cant find any air leaks and if i cover the Brass inlet on throttle body it stalls the car so im thinking no air leaks.

Im not sure if you can see in the video after revving it up it holds the RPM for a little while before dropping the RPM ?
Its much worse when you pull up at a junction holding the RPMs at 1500 or above when cold.

Not sure if the video shows the problem well enough as it was just sitting.

here is a link to it on youtube as was to big for forum.
https://www.youtube.com/watch?v=vO3XPBMG-0g



Any help appreciated.

[Rick-sta]

Mine was doing a very similar thing, turned out it was 2 things:

1. I had a split in one of the breather hoses. Replaced the hose.
2. I had a sticky throttle body. Gave it a good clean with carb cleaner which sorted it.

[janker]

Originally Posted by Rick-sta

Mine was doing a very similar thing, turned out it was 2 things:

1. I had a split in one of the breather hoses. Replaced the hose.
2. I had a sticky throttle body. Gave it a good clean with carb cleaner which sorted it.

Hi and thanks for fast reply,Ive checked all breather pipes for cracks or leaks but everything looks sound,Ive cleaned throttle body many times and even tried a secondhand throttle body but the problem persists.

[Madderz]

I'd suspect a fault in the pedal, remove it and clean whatever you can, can't hurt.

My Astra Van had a similar thing, I hit the pedal box with a hammer and that sorted it lol

[paulcnb]

My 2003 ZT190 has the exact same problem.
Like you, I have checked hoses and throttle body to no avail. It has to be something simple - but just what, eludes me.
The car performs beautifully in all other respects. I'll follow your thread in the hope that someone has an answer for you (us).
Regards

[Rich in Vancouver]

Mine was the throttle body. I gave the butterfly pivot and spring a couple of good soakings with penetrating oil and it freed up.
I suspected it was the throttle cable and ordered a replacement but that's now sitting on the shelf as a spare.

[janker]

Originally Posted by Rich in Vancouver

Mine was the throttle body. I gave the butterfly pivot and spring a couple of good soakings with penetrating oil and it freed up.
I suspected it was the throttle cable and ordered a replacement but that's now sitting on the shelf as a spare.

Hi Rich
Ive checked all butterfly pivot,Completely free and cable also foot pedal linkage even replaced the entire throttle body from another car but as yet no luck.

Cheers julian