P38 lpg/petrol running problem - Land Rovers Only

woodcotegreen · 09-11-2005, 10:44 AM

Hi there, i was wondering if anyone can help me with this one, I have a 1998 4.0 P38 with GEMS management and an lpg conversion, the car runs perfectly on lpg, smooth stable idle, pulls well, revs freely, etc etc, however when it is switched back to petrol, it has a lumpy uneven idle, is is slow revving, it has a hesitating spot between 3,000 and 4,000 rpm when I think it has a misfire, as soon as it is switched back to lpg all is fine, any ideas?? many thanks James

shiftech · 09-12-2005, 02:28 PM

probably 1 of the fuel system sensors.If you have a closed loop system then the throttle position sensor is probably ok as the lpg uses it.A good place to start is the rubber pipe between the plenum and the air flow meter.Check it for splits,cracks and leaks on the joints.Check the left hand and right hand side rocker cover breathers are in place and in good nick.Have you had a blow back when on lpg?
If you need any more info just ask

09-11-2005, 10:44 AM	#1 (permalink)
woodcotegreen Member Join Date: Sep 2005 Posts: 1 Gallery: 0	P38 lpg/petrol running problem Hi there, i was wondering if anyone can help me with this one, I have a 1998 4.0 P38 with GEMS management and an lpg conversion, the car runs perfectly on lpg, smooth stable idle, pulls well, revs freely, etc etc, however when it is switched back to petrol, it has a lumpy uneven idle, is is slow revving, it has a hesitating spot between 3,000 and 4,000 rpm when I think it has a misfire, as soon as it is switched back to lpg all is fine, any ideas?? many thanks James

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Remove Advertisements Sponsored Links
Land Rovers Only - Land Rover Forum Advertisement

09-12-2005, 02:28 PM	#2 (permalink)
shiftech Member Join Date: Sep 2004 Location: Wales,Uk Posts: 76 Gallery: 0	probably 1 of the fuel system sensors.If you have a closed loop system then the throttle position sensor is probably ok as the lpg uses it.A good place to start is the rubber pipe between the plenum and the air flow meter.Check it for splits,cracks and leaks on the joints.Check the left hand and right hand side rocker cover breathers are in place and in good nick.Have you had a blow back when on lpg? If you need any more info just ask

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)