1989 Vn Calais- Lpg Impco Gas Backfire!!!!!

[epiic89]

Hi i ahev had my Vn Calais for about a year. and over the past 2 months i have had constant problems with starting the car and backfiring.

I have changed the diaphragm in the mixer. and the 2 diaphragms in the other larger mixer. The strange thing is it will not always backfire, i can push it very hard and nothing will happen. yet when i drive carefully or slowly it will happen.lol.

i believe that my leads and sparks were changed not too long ago. i did believe it was thr diaphragms that caused the backfire but even after replacing all of them it still back fires. help please.

[dufus]

Get it tuned

[vr-man]

had problems same as yours in my vp ,i changed coil pack and the problem went away. but would say get it tuned and change leads. my gas guy reckons leads need to be replaced every 20,000klm.

[epiic89]

ah k , thnx il have try them....

[poweredbycng]

Bad ignition leads to backfires. Change plugs, leads, check coil pack, and if all that fails, get your gas system tuned. Also, start the car on petrol and change over to gas when the engine hit 30C or so. Not only will you avoid backfires, but you will also avoid a regulator freeze-up.

Regards,
Dave

[VNwazza]

It may be that your (petrol) fuel pump has had it. I had the exact thing with mine and thats what it was. You should be able to hear the pump engage when you put your ignition on as it continually runs even when you are on gas, as it just cycles back to the tank. If there is no petrol getting in at all, she backfires just as you described, my air filter box was smashed! Thats how mine was anyhow, but I hope to have helped you out.