Rich mixture problem
07-30-2013, 09:59 AM
#1
Rich mixture problem
Trying to identify cause of very rich mixture. Most sensor related causes ruled out but I am wondering what the 'normal' calculated load at idle [850 rpm -TPS at 19%- MAF =1.2lbsmin] should be. I get a value of about 40% and that sounds too high - maybe high enough to put me on the wrong place on the fuel/air map? If that is close to normal I will have to go back to looking for a mechanical fault with injectors/fuel regulator etc.
OK... more info from scanning tool - the left bank fuel injector pulse width/time is significantly (50%) higher than the right all across the rpm/load spectrum. Does anyone know what would cause this?
Thanks.
OK... more info from scanning tool - the left bank fuel injector pulse width/time is significantly (50%) higher than the right all across the rpm/load spectrum. Does anyone know what would cause this?
Thanks.
Last edited by IanC.; 07-30-2013 at 12:42 PM. Reason: More info
08-12-2013, 06:49 PM
#2
Still looking for info on this - Aug 11, 2013
Does anyone have some 'normal' Scan tool parameters for the 4.2l F150? Specifically closed loop values for MAF volts or Lb/min at idle; calculated LOAD at about 800 rpm; Throttle Position volts [at idle]; and most critically the PULSE WIDTH for Banks 1 and 2 at idle, under closed loop. With a set of these values from a 'normal' engine, perhaps I can identify the problem with my super-rich 1997 F150. Thanks for any relevant info you can supply. [All other likely sources of too much fuel for a fixed amount of air have been checked]
Does anyone have some 'normal' Scan tool parameters for the 4.2l F150? Specifically closed loop values for MAF volts or Lb/min at idle; calculated LOAD at about 800 rpm; Throttle Position volts [at idle]; and most critically the PULSE WIDTH for Banks 1 and 2 at idle, under closed loop. With a set of these values from a 'normal' engine, perhaps I can identify the problem with my super-rich 1997 F150. Thanks for any relevant info you can supply. [All other likely sources of too much fuel for a fixed amount of air have been checked]
