hi i have a bmw 540 v8 runs perfect on petrol but when it switches to gas it runs as if its missing on one of the cylinders,i had it checked out yesterday and it showed that computor on the car said it was running fine on both petrol and gas, but it is still missing.i have had the plugs changed on the last service but it made no difference.
how do i find the problem and rectify it?
change the plugs, replace the coils.the car runs ok starts and drives ok but it just niggles me and i,m trying to eradicate this fault.
dave.
seems to be missing on gas
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- Posts:7
- Joined:Wed Aug 20, 2008 8:00 pm
- LPG System:autogas2000
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- Posts:288
- Joined:Mon Sep 03, 2007 8:48 pm
- LPG System:Prins VSI
- Car:BMW 540iA Sport
- Location:All over the UK
Re: seems to be missing on gas
If you've driven it on petrol only for several days and are certain it runs perfect on petrol and there are no error codes stored, then it could be a slight LPG fuelling problem. Check the fuel trims when driving on LPG.
Mak
Site Owner
2001 BMW 540i Auto Sport Saloon
~300 BHP; ~320 ft/lbs, Prins VSI system
Site Owner
2001 BMW 540i Auto Sport Saloon
~300 BHP; ~320 ft/lbs, Prins VSI system
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- Posts:7
- Joined:Wed Aug 20, 2008 8:00 pm
- LPG System:autogas2000
Re: seems to be missing on gas
how do i check the fuel trims or will this be a diagnostic check?
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- Posts:288
- Joined:Mon Sep 03, 2007 8:48 pm
- LPG System:Prins VSI
- Car:BMW 540iA Sport
- Location:All over the UK
Re: seems to be missing on gas
If you have a 2001 or later car, you can check them easily with handheld OBD-II reader plugged into the diagnostic port in the car. If you have an earlier car, you adaptations need to be checked via a diagnostic programme using the 20 pin socket under the bonnet. Either way, make sure the car is running perfectly on petrol to eliminate the petrol side of things.
Mak
Site Owner
2001 BMW 540i Auto Sport Saloon
~300 BHP; ~320 ft/lbs, Prins VSI system
Site Owner
2001 BMW 540i Auto Sport Saloon
~300 BHP; ~320 ft/lbs, Prins VSI system