1990 Volvo 760 turbo with 143,000 miles.
In hot weather the car stalls frequently at idle unless you keepthe acellerator pressed. About 3 weeks ago the Check Engine Light came on.
About the same time, this normally smooth shifting car, the auto transmission began shifting a bit harder. It would appear that the engine has to rev higher than normal before shifting into a higher gear.
The diagnostic codes are :
Fuel Code Check: (Plug in position 2) Code 1-2-1 "Mass airflow signal
absent or faulty"
Ignition Code Check ( Plug in position 6) Code 1-4-3 "Knock sensor signal
faulty or missing "
Could these be related in any way?
Any suggestions on how to troubleshoot this from here would be greatly
appreciated.
Thanks
|