The V8 Owners Forum -

i have had my lpg running on my efi engine for a while now , but i have just discovered that when i switched over to lpg that the petrol pump has been still running
i used a relay to switch the sense wire coming from the NEG side of the coil to the ECU (flapper) , but i have discovered that all that has been doing to to switch off the injectors , as soon as the air was opening the AIRFLOW METER the pump was switched on
i have now added another relay to switch the pump off too ..

how have you done it ??????

I know my pump runs while on lpg, not sure if its supposed too or not but even though running on lpg it still seems to use more petrol than just a start up amount.

this how iv'e done mine

http://www.putfile.com/album/182530

i had the coil one to start with (on the left) , but as the pump was still running i added the on the right too
i don't like it really , but maybe there's a better way ????

My pump runs whilst on LPG, always. Gives a quicker changeover back to petrol.

Chris.

Hi chris , did the picture make sense ?
i spoke to TINLEY TECH just now and he said that yes the pump runs , the only problem is when it runs out of petrol and you switch to gas it could burn the pump out , and if your like me and run it on petrol fumes ...lol
i have fitted the extra relay (see the picture) and it seems to switch back to petrol as quick as it did before , then i only ever use petrol to start and warm in slightly so as i avoid icing anyway , so not really a problem
are you going to north weald for the 11th may Chris ?
it would be nice to meet up and see your conversion

Circuit looks OK - basically when on LPG, it cuts the spark signal to the ECU and also the power to the fuel pump. Can't see a problem with it.

Not planning to go to Weald - my motor would be an embarassment to a scrap dealer!

Chris.