Vs backfiring under load

[stiffa]

My vs wagon is backfiring under load when then car reaches operating temp. Doesnt do it when cold.
Ive changed the leads and the plugs. Also had the coils checked ( one changed) and had a new DFI module replaced. Still backfiring

Anyone with suggestions?

[hako]

Welcome to the forum. Are you by chance running the car on gas?

[stiffa]

Yes the car is dual fuel. But i am having the problem when running on either lpg or petrol

[strgas]

what spark plugs and gap are you running ? have you checked for vacum leaks at the manifold and injector seal etc etc ??

[stiffa]

i dont know the gap i have got - put the plugs in as new and was advised to close the gap slightly. Don't know how to check for vacuum leaks at those locations - but more than willing to give it a try if i can get some basic instructions.
THANKS

[strgas]

recommended plugs for gas BP7EFS gapped to 1.0 mm . grab a can of carby clean and spray around the manifold where it meets the heads and where the injector seals sit listen for changes in rpm , check the vacum hose from the throttle body and the rear of the manifold for fittment and condition , check for bad connections made by the gas fitter dodgy earths are common , check the intake hose for cracks and air leaks again with the carby clean , who did the gas install and what system have they used ???

[Lady Calais]

best plugs for gas are Toyota plugs - they are Denso T20EPU15 's don't re-gap them.

[calais24/7]

Could be your air flow meter also

[stiffa]

Thanks for all the tips guys ill give them a go