Suppose i should start from the beginning.
Im currently attemping to put the upper throttle body section from an M44 engine onto my M43 engine. The sizes are a perfect match but the difference is the M43 has a single barrel throttle body and the M44 is double barrel.
Since i was doing the air intake i bought myself a cone filter to put inside an insulated heatbox i have ready. The problems started when i decided to test the "boy racer" way of seeing if the cone itself increases power. Now i already know it doesn't due to taking in warmer air, but just for a laugh i tried it.
(From here on you will have to excuse my complete lack of knowledge of all the technical names for the parts so i will do my best to describe them).
The only problem is the tube that goes between the throttle body and the standard filter won't take a cone filter. So i fitted part of the pipe from the M44 engine, which takes the cone. However during the change a plug (between the filter and the throttle body) needs to be removed. (Incidently this plug section is the part i changed). Once this plug is removed the engine will not idle properly.
With the M43 pipe.
The M43 pipe has a sort of moveable door inside the box this plug plugs into. Im guessing that senses airflow and changes the fuel needed in conjunction for when you put your foot down. However this doesn't explain the poor idle.
With the M44 pipe
There is no door, its just a straight pipe. But when you go hard on the throttle the car hits and almost deadly flat spot and struggles to accelerate at all until it hits the higher rev range.
So i was thinking, is it possible for the engine to get too much air, or is that sensor in the M43 a way of ensure there is enough fuel for when you put your foot down. As you can probably already tell, the plug from my car will not fit on the M44 pipe. Which has a different size plug and a different way of sensing airflow.
Any questions just ask, i'll be a happy to provide pictures if necessary. Also the throttle body thing might not work, but i'll start another thread for that when i get to it so we dont drift from topic.