1997 4.6 runs rough

Demondog2007

New Member
May 28, 2019
1
0
1
48
Pennsylvania
1997 mustang gt replaced fuelpump due to no pressure at rail and wouldn’t start i have pressure now but it starts really hard cranks over and if i give it press accelerator pedal it will start and barely stay running but missing really bad and breaking up more i give it gas it does run a little better but barely stays running without constant acceleration at idle i replaced all plugs and wires and still not running correctly anything else i can check
Thanks
 
  • Sponsors(?)


wmburns

SN Certified Technician
Aug 14, 2009
5,361
417
164
Houston Texas
Do you have an ODB2 scanner? If so, it might make short work of your problem.

Otherwise start by checking:
  • Double check that the intake vacuum reference line is connected and leak free.
  • look for a vacuum leak between the MAF and throttle body.
  • Double check that all electrical connectors have been re-connected especially the IAC, TPS and the CAM sensor.
  • Check to see if the IAT and ECT sensors are sending "reasonable" values.
ForScan ODB2 scanner w ELM327 USB

1996+ Crank with no start check list