Gentlemen, can you help me? I have a 72 galaxie with a 400ci on dual fuel. It is running a single 425 impco mixer and convertor.I have issues with a stumble when running on petrol as I accelerate that isn't there if I replace everything and just run an aircleaner. I have discussed this on Fordmods before and have been thinking about it. After some other advice I believe that the diapraghm in the mixer is fluttering/closing off and also possibly affecting the vacuum in the carby.The smaller 300's have a cable actuation to prevent that happening. I have been thinking on this and have an idea.
i either:
A) get another mixer etc and then run two. There should be two intakes there fore promoting airflow. This may lead obviously to running dedicated LPG only,and removing the carby altogether but I am not there yet. Even though this is A it is actually plan B
B) introduce another airflow into the carby after the mixer somehow. I may completely reman a top hat out of sheet metal for another intake ( I could also make a slightly shorter one as bonnet clearance is minimal!!) but if I go that way I would kick myself if I went to a twin mixer as unless I did it properly it would be a complete redo. So much for all the info, My question is ultimately this!! I was considering using an electronic throttle body to acheive a closed off intake when running on LPG therefore nothing changes there. BUT when I activate back to petrol I can have a signal to go the throttle body to open it. Apparently though the signal to the stepper motor is a closed loop (?) as it needs to have some control. Can I put a signal into it just like the lock off valves that will hold it wide open? Has anyone done anything like this and if so what, why how, easier?

The sound of silence?? nothing here?