Vn Commodore Sedan Series 1, jerking at 80 kms to 90 kms.

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Hi All, Just wanted to know if anyone has had a similar problem with their v6 making jerking or pulling motion while under load increasing speed only around 80kms to 90kms an hour??
It's weird that it does not do it at different other speeds but only 80kms to 90kms hour not sure what this could be.

 

[greenacc]

Transmission not dropping into 3rd gear. Try the same speed with gearstick in 3rd.
Might need a service too, spark plugs etc...

 

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Hi, its an auto, Got new spark plugs already engine itself if running fine the leads are about a year old just put a new coil in it also checked earths as well?

 

[greenacc]

Yeah I mean put the shifter in 3rd and see if it still happens

 

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Ok will give it ago thanks.

 

[91SS]

On my v8 when I had this issue turned out to be a blicked catalytic converter.

 

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Yeah I mean put the shifter in 3rd and see if it still happens

Hi greenacc I've tried the car in 3rd and it does not do that only in overdrive (Blue D)???

 

[Immortality]

I'd try and injector flush and fuel filter.

Wouldn't hurt to check the fuel pressures either.

 

[greenacc]

Hey mate, that makes me think it's either struggling under load or the trans needs a service.
80-90 is usually the speed the trans switches from 3rd to 4th when in drive but it's also where the engine is doing low revs under load.
Make sure your plugs leads and coils are good, fuel system is good, then maybe look at oxygen sensors.
My VE used to do this a fair bit and it disappeared when I fitted new oxygen sensors believe it or not. Probably because the mixture was a bit off with the old sensors so wasn't making full power.

 

[Immortality]

If it was an ecotec I'd say it was a lean mixture/lean cruise miss and most likely an ignition problem but the VN's been MAP based are a bit different.