map sensor

respectirocz
09-23-2005, 03:49 PM
why does my carb'd vehicle have a map sensor?

Dave89IROC
09-23-2005, 05:23 PM
it is a ccc carb originally, computer controlled carb, it had a TPS in the carb as well, used to calculate, among other things, spark advance and TCC control

90rocz
09-23-2005, 11:37 PM
It has a major affect on fuel mixture, by sensing the "Load" placed on the motor by measuring engine vaccum.

respectirocz
09-24-2005, 11:18 PM
i understand using the map sensor and a tach reading to determine "load" in order to determine pulse width and thus mixture (speed density)

i understand in the standard carburator, the carburator acts like the modern mass air flow sensor, the amount of air passing through the carb determines how much fuel is dumped

i thought in the ccc carb the tps would determine the desired fuel ratio and the oxygen sensor was feedback for the metering solenoid
the metering solenoid pulsing 10 times a second would determine ratio by its duty cycle, and the carb would again use the pressure differential to determine how much available fuel can be dumped, i say available, meaning what ever the metering solenoid allows


so
is the map sensor really needed?

90rocz
09-25-2005, 09:30 PM
thought in the ccc carb the tps would determine the desired fuel ratio and the oxygen sensor was feedback for the metering solenoid
the metering solenoid pulsing 10 times a second would determine ratio by its duty cycle, and the carb would again use the pressure differential to determine how much available fuel can be dumped, i say available, meaning what ever the metering solenoid allows


so
is the map sensor really needed?I'm not sure what you intensions are? I know what you are saying, carb's are basically MAP sensors themselves, by using air pressure drops to adjust fuel flow, via jets and metering rods. But it was design to use the input from the MAP in its calculations so I'd say yes. It might scew other parameters like ignition curves etc..?? I'm NOT a carb expert...But for a performance app I'd ditch the CCC-feedback carb for a Regular carb, they don't have the best track record for performance.
(It's kinda like the old addage, "the fancier you make the plumbing the easier it is to clog the drain."...over-engineered that carb if you ask me.)