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VT RPM drop at idle

Bezzey

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This started about a week ago. This is what I have observed thus far.

Approximately 20seconds after start up If I am in park and engine is idling, it drops from 1,000RPM to just above the 0RPM mark for about 2 seconds max then jumps back up to 1,000RPM. It feels like a misfire sort of vibration when it drops. I have not noticed it while under load or at high RPM.

Has anyone had this before or heard of this? I have searched the forum but all I could find was people talking about it happening under load or at high RPM.
 

accentstencil

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It could be a faulty spark plug lead, I've had similar symptoms and it was the a bad lead. 1,000 RPM is a bit high at idle.
 

Bezzey

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mattyj23

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Mine was doing this was a dodgey coil also blocked fuel filter have had it do that before too
 

Bezzey

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Decided I'm going to change plugs and leads for 2 reasons. It may fix it & I don't know how long ago the previous owner changed them so good to give them a refresh. If that doesn't fix it then I'll try cool pack I suppose!
 

Vsfan95

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Try changing your Idler Control Valve its the black sensor on top of the throttle body. Mine did the same thing it starts and it acts like its got a lumpy cam. They are about $70 at repco.
 

Bezzey

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Yeah lumpy cam is a good description! Hmmmmm now I'm not sure what to replace. I might just do all for peace of mind & as a means of fixing the problem. I'll do each part one at a time (ie; plugs, go for a drive. leads, go for a drive. ICV, go for a drive) so that if one fixes it I know and can pass on information for anyone that happens to search for the same problem and finds this thread once it is fixed.
 

accentstencil

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Yeah lumpy cam is a good description! Hmmmmm now I'm not sure what to replace. I might just do all for peace of mind & as a means of fixing the problem. I'll do each part one at a time (ie; plugs, go for a drive. leads, go for a drive. ICV, go for a drive) so that if one fixes it I know and can pass on information for anyone that happens to search for the same problem and finds this thread once it is fixed.
I'd start with the leads, I've lost count of the number of faulty leads I've had over the years, never a plug. You mentioned earlier that you haven't replaced them since you have had the car, if that is a fair while I would definitely change them because the don't last a real long time from my experience.
 

Bezzey

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I'd start with the leads, I've lost count of the number of faulty leads I've had over the years, never a plug. You mentioned earlier that you haven't replaced them since you have had the car, if that is a fair while I would definitely change them because the don't last a real long time from my experience.

Ok thanks man I'll start with the leads then! I've had it for about 5 approximately now.
 

Bezzey

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Update:

I changed the leads last Thursday. No change at all. I've got a new Idle Control Valve coming in the mail so I'll see how that goes. Does anyone have any idea about replacing it? Ive had a look around the forums but no luck.
 
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