An out-of-range ECT (engine coolant temperature) sensor is more likely. This sensor overrides all other computer fuel-enrichment controls on a cold engine. A cold engine needs a longer injector pulse and adequate fuel pressure to overcome the mechanical resistance in a cold engine.
Jim O’Neill – Chino Autotech Inc., Auto Club SoCal AAR
SAE Int’l SoCal Section Board of Governors,
Vice Chair, Service Technology Programs
NASTF Service Information/Communications Committees
Auto Value/Bumper-To-Bumper CSC Nat’l Council
ASE CMAT-L1, CA. Smog Check Technician
AMI AAM Accredited Automotive Manager