Hi,

My V6 petrol/lpg Alphard runs great. But when I stop at a traffic light say, if I put it into neutral it will (now) often cut out. It re-starts instantly, but if I then put it into drive, and keep my foot on the break, it will tick over as good as ever.

I was wondering of it could be a dirty throttle pot as, a few times, pulling out of a tight T junction it has 'lurched' with throttle going up/down before settling down on the straight.

When I have run out of LPG, so running on Super Unleaded, the cutting out at neutral persists when the revs drop to tickover, so I don't think it is any issues with the LPG. The problem can happen after a journey of 70 miles or 5 miles, so it is fully warmed up.

Under normal driving the car has never given any issues and continues to drive strongly. It is now on 120,000 miles.

Hi there!

It's certainly worth the effort to clean the throttle body, if only to eliminate it from the enquiries!

I did ours when I took it apart to change the plugs, it was quite mucky.

If it's bad enough, I can see it may stick coming off idle.

Ours is on lpg too!

Cheers, Nev

Edited March 3Mar 3 by BigNev

Many thanks, will check it out. I have never taken a throttle body apart before, so I will wait until a weekend.

Cheers

I cannot speak about lpg, but it is not necessary to put the vehicle in neutral at all.

I have driven automatics for years (and manuals) and there is no need to deselect the auto-gearbox at traffic lights.

Obviously, you will need to keep your foot on the foot brake, otherwise your vehicle may creep.

Could be a dirty throttle body or MAF sensor, you can get MAF spray cleaner on eBay or Amazon. If you have recently changed ethanol rating fuel the ECU has to relearn the idle mix so will take a while to settle

Interesting, thanks/ I have only ever put super unleaded in it, but I guess the source could change, and we are in the hands of the importers....

As I say though, it does it on lpg as well, which it has been using for the last 80000 miles!!