Hello,
New here so please be nice

I have an EL Falcon Automatic on Dual Fuel (Non Factory and dont know the brand or insataller sorry)
It runs really nice on Gas, smooth and great economy (according to the trip meter 6.0 l/100km on the highway at 100km/h) but on petrol its a strange thing.

If i accelerate hard or softly its really rough until 2000/2200 rpm or so with no guts at all. After that it takes off and runs really smoothly. Could this be a fuel pressure problem or is it something as a fuel filter or blocked injectors? A mechanic said to me that dual fuel cars just get like this, not sure if i totaly believe that... The car has been doing this since i bought it.

I have tried different fuel types and generally run 98, the only thing i have been able to try is injector cleaner. Would like to know a few ideas about what could be wrong. Any help is much appreshiated!

So its idling like a bucket of s**t on petrol? I have had this and it ended up being the vacuum hose on the PCV valve on the rocker cover have come off. Check all of your vacuum hoses around the injection manifold. Check to see if any have come off or splits etc.

LPG is more forgiving witch is why its running better on gas.

Hope this helps.

I had a similar problem with EF. The car use to run fine on petrol, then one day the car just didn't want to accelerate on petrol...had a sort of hesitation under load. I thought bad fuel, or injectors, or fuel pressure. I tried a few goes with injector cleaner, but it never got any better. In fact, during winter it was better, than summer.

I then had an odd problem on LPG, with the very occasional stall. This turned out to be the Tacho Amp module that they connect when fitting the LPG. Once this was replaced, the car ran fine on gas, and interestingly, it is now running on petrol much better.