Newbe with bmw V12 cutting out

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jabba
Posts: 25
Joined: Sat Nov 24, 2007 10:34 am

Re: Newbe with bmw V12 cutting out

Post by jabba » Mon Dec 03, 2007 9:52 pm

Suprise Suprise! - my X5 stalled when crusing up to a roundabout this evening - this is after the installer having it for 4 days and saying he couldn't find a fault. I guess the engine is too complex for the prins system if the ecu is dropping a couple of cylinders (as you mentioned) and the gas system can't handle it and it cuts out!

Really at the end of the (stalling) road with this - lost my patience with Herts Autogas because I think they (a) can't fix the fault and (b) can't be bothered. I certainly can't be coffing up each time for a hire car whilst they drive around in it.

If anybody has any other suggestions then please let me know!.

mak-uk
Posts: 288
Joined: Mon Sep 03, 2007 8:48 pm
LPG System: Prins VSI
Car: BMW 540iA Sport
Location: All over the UK

Re: Newbe with bmw V12 cutting out

Post by mak-uk » Tue Dec 04, 2007 11:42 am

Have you tried Alternatech Fuel Systems? They are the UK distributors of the Prins VSI system and the experts - if they cannot get it working, I doubt anyone else could.
Mak
Site Owner
2001 BMW 540i Auto Sport Saloon
~300 BHP; ~320 ft/lbs, Prins VSI system

jabba
Posts: 25
Joined: Sat Nov 24, 2007 10:34 am

Re: Newbe with bmw V12 cutting out

Post by jabba » Tue Dec 04, 2007 4:39 pm

If it's Alternatech in Andover then it has just been there for 4 days. A guy called David King had my car for driving to and from home covering over 200 miles and he said it never stalled once. Still find it bizarre that when running on lpg the rev counter undulates up and down when slowing down and this behaviour sometimes results in the car stalling. David King said this behaviour (i.e. the rev counter undulating) is to be expected on a car like this. Not sure why this is to be expected on a car like mine and it cetainly doesn't do it when running on petrol. I think this rev counter undulating is key to finding the problem and David King has said to me he did see this happening but seems to shrug it off. :(

mak-uk
Posts: 288
Joined: Mon Sep 03, 2007 8:48 pm
LPG System: Prins VSI
Car: BMW 540iA Sport
Location: All over the UK

Re: Newbe with bmw V12 cutting out

Post by mak-uk » Wed Dec 05, 2007 5:41 pm

Yep - they are the people.

Does the rev counter not do this on petrol? Have you run it for an extended period on petrol and seen if any faults come up?
Mak
Site Owner
2001 BMW 540i Auto Sport Saloon
~300 BHP; ~320 ft/lbs, Prins VSI system

jabba
Posts: 25
Joined: Sat Nov 24, 2007 10:34 am

Re: Newbe with bmw V12 cutting out

Post by jabba » Thu Dec 06, 2007 10:25 am

Doesn't display the same behaviour on petrol. Have run it on petrol for over a week and never had any problems.

I have recently changed the idle control valve because an error was coming up saying "DSC Inactive' and although it sounds nothing related to the actual fault I read the code and it says 'Idle control valve mechanically stuck'. Anyway, changed that and the DSC Inactive warning light no longer appears but the stalling problem has gone on since I got the car converted in July 2005 and also since changing the idle control valve so I don't think this is the problem.

I am probably going to drive the car down the Alternatech again and show them the behaviour I am talking about and see if that moves things along a bit.

Knightkiller
Posts: 15
Joined: Sat Sep 29, 2007 8:04 pm

Re: Newbe with bmw V12 cutting out

Post by Knightkiller » Sat Dec 08, 2007 7:07 pm

My 728i did this for three days after having it serviced so was able to pinpoint the problem if its any help. Same problem, it would run fine for hours then bang it would cut out completely.

It was when I had it serviced I complained about the map not quite being to my liking and it was too quick to switch over to petrol when giving it the beans. Went back, let the computer set the map as it was done originally by hand (IYSWIM) and its been spot on ever since. The guy showed me the difference between the software to set my map and the prins and omvl and all the other ones he had the map setting software for. The one on my system was so much more advanced than the others, was quite shocked to see the difference. Had so much more detail and variable that you could set/ My kit is AC or something like that.

Anyway.... long story short.... mine was down to a change in the map, drove around with the laptop on for a couple of hours as it adjusted itself and has run spot on ever since. And this car can run for 10-12 hours at a time so no mean feat. :mrgreen:

HTH

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