Please help -VN idle issues

[Norco]

Hi Guys,

I have had my VN calais auto (no mods) for about 9 years of flawless service, but recently (at about 250,00km) the idle when cold has become rather rough and it the tacho is bouncing around a bit at idle.

Also if you put the foot down a bit hard, the revs bottom out and it almost stalls. Everything seems fine when it warms up or under gentle acceleration but its getting anoying.

The only other thing i have noticed is an annoying exhaust noise, like the pipe is touching the bodywork somewhere under the car (or is could just be loud its an old stock system). but this to goes once it warms up.

The local mechanic (a new guy) has suggested that the " transister or resister moduls" need to be replaced (at a cost of about $400) but i'm pretty such sure his full of it.

Am not terrible handy with a spanner, but at east if i Know whats going on - i won't get robbed blid by a mechanic - Thanks muchly..

[coolvxss]

My car was idleing realy bad on cold mornings and ran bad when cold like yours. I put some injector cleaner in the tank and took it for a long drive and by the time the tank was empty and filled up again it was fine. I havnt had a prob since. Could be the same prob with yours but not sure.

[Shortstuff]

I would start by looking at simple things. Check the exhaust isn't blocked as this can happen if the Catalyst starts to break up.

Possibly try cleaning the throttle body which is easy to remove if you have a repair manual. If you disconnect the rubber air intake pipe from the throttle body (you only have to undo 2 jubilee clips to remove the air intake hose) then you can have a look inside it first to see if it looks really black and horrible or relatively clean in there.

We used to gt a lot of Vauxhalls coming in with those symptoms when I was in the UK, but I can't think of the solution right now!!!
I think it was the throttle body being very dirty but not 100% at the moment.

[Norco]

Thanks guys, will give them both a try - could be the Cat starting to give out, that might explain the exhaust noise too - seems to be coming from that area.

Cheers..

[nopatcla]

have you checked your air filter, sounds like a dirty / blocked air filter, then check plugs and leads, then O2 sensor , coolant temp sensor, and injectors. BUT first check the air filter