Hesitation / thump /miss when accelerating from 80km/h

[tepaus]

Hello all,

Last night we took a 4 hour trip in our 2005 VZ (105,000 km) when accelerating from 80km/h back up to 100km/h, we noticed a miss and an almost a thumping when the accelerator was pushed down. When it did get back up to the 100km/h speed it seemed fine. Any ideas what we should be looking for? - i'm suspecting crook leads but just wanted to know if anyone else has experienced this.

Many thanks in advance.

 

[holdenvtman1123]

it is quite possibly the cranckshaft balance wheel. check the rubber around the center of the pulley

 

[jetboy]

it is quite possibly the cranckshaft balance wheel. check the rubber around the center of the pulley

il second tht coomon prob those harmonics

 

[-**wHiStLe**-]

Harmonic balancer shouldn't have worn after 5 years..
Or are they really problematic with VZ's?
Plus if it's so gone as to cause problems you would probably hear it (like a ****ed bearing).
From my experience anyway

 

[mattsv6]

I had a similar issue with my VZ that started around the 100,000k mark... It turned out to be the ignition coils which were not firing the spark plugs properly and causing a miss.

This only happened when using medium to heavy acceleration or trying to build up speed (say from 80-100) in 5th gear.

Hope this helps.

 

[andyman]

ive never heard off balancer problems on alloytecs, the crank signal does not run off the alloytec balancer either,

id be leaning towards coils, seems to be a common thing around the 100+ km's at this age, mine seems to be hesitating and getting worse in that way so ill have to do some testing sometime soon

 

[dave1979m]

I ham having similar probs with my 2004 model VZ. Auto Electrician is telling me its the ECU. Can you replace them with a used one from a wreckers or do you need to have them programmed for the car??

 

[bigdaddycool]

VZ's seem to have alot of electrical issues. dave1979m, perhaps it is the ECU, maybe it's just something shorting for a second here or there....

Try a spark plug change ....... doesn't take long. If that doesn't work, have ur coils checked by an auto electrican. Both are alot cheaper then an ECU.

 

[mattsv6]

I agree, could be a cheaper solution to your problem.

-Matt

 

[impulsive]

BDC busting out the moves mate, thanks for posting some useful info as late!