VP Idle.....Again

[nathanashton]

Hi Guys,

I know this tends to come up fairly often but Im having problems with the idle on my VP Calais. Basic symptoms are
1. "Bouncy" idle. It will idle between two figures and bounce between the two alot. Also, it im idling up to the lights the revs will bounce all over the place.
2. Idle "sticks" at low rpm. Bit hard to explain, but if i pull to a stop the idle will drop down real low, say 200, run like crap then slowly work its way back up. Ive had the car stall before when driving slow because of this.
3. Exhaust tip gets black pretty quick and Im positive i can smell fuel fairly often.

Had it looked back months ago and after being stuffed around they replaced the fuel pump and it ran great for about a week, then back to normal. Cost me a fortune in labor for them to do this.

Can someone give me some clues so I can point the mechanic in the right direction? I don't want a fuel pump costing almost a $1000 again


Cheers

[DAMQIK]

sounds like me VN lol, does it idle good when its in park? mine runs great in park, but in reverse or drive she gets a bit rougher and drops the revs. a grand for a fuel pump?
wat the

[nathanashton]

Runs pretty bad just sitting there. Idle is all over the place and hiccups every now and then. Real pain. As for the fuel pump, they spent 3 days trying to work out wat they were doing. Something about fuel pressure. Mostly labor charges. I got ripped

[vn calais manual]

you did indeed.

[nathanashton]

Yeh i know......anyway that's why im after some ideas so I can point the mechanic in the right direction. Even if someone could recommend somewhere in Brisbane, preferably on the Southside

Cheers

[DAMQIK]

have u checked the go cable on the throttle body? its not to loose or anything? how old are your leads? its either fuel or electrical, soz mate im down in Vic

[greenfoam]

Alot of VN V6's run like that, mines gone through stages in it's life where it's had a hunting idle for no apparent reason, I could usualy tune it out by changing a few things around but like the others said it's just they way they are....... crapy things

[vn calais manual]

crapy things

burn him!

lol mate id cover the basics like clean out the throttle body and idle solenoid, check the adjustment on your cable.

[V85000i]

it could be a tired alternator, at idle it don't make enough charge to power all the electrics, eg. fuel pump, injectors, coils, etc.

[vn calais manual]

also possibly fault fuel reg.

[Cheap6]

The throttle body/IAC valve clean is easy and a good place to start.

Also:

It could be that the IAC valve is at the end of its useful life - they tend to get sloppy in the worm drive and stick.

Many people insist on altering the throttle stop screw. It should have a green tamper evident cap over it. If not, it's suspect. (I know, sorry, I've posted that before but it's one of my pet peeves).

Something else to check is the throttle position sensor - they can get a wear spot in the contacts that makes intermittent contact and the ECM doesn't know where it's at.

Poor basic engine mechanical condition - low/uneven compression, vacuum leaks, stretched timing chain, worn cam lobes - can also cause a dodgy idle.

A vehicle speed sensor fault.

Any fault codes?

[nathanashton]

Thanks for the replies. I haven't touched anything for a few months. With the help of a friend a while back we cleaned the throttle body and IAC valve, which was pure black and filthy. Remember there was a code for one of the sensors which we replaced. Cant remember the damn name of the thing. Plugged in to the exhaust lol. Nothing helped. Been driving me crazy every since