Fuel or spark issue

1995 GMC TRUCK
200,000 MILES • 5.7L • V8 • 4WD • AUTOMATIC
Avatar
GARY M AGNEW
  • MEMBER
  • 1 POST
GMC k1500. no o2 sensor or cat headers. When i am driving and its wet it acts like it is loosing fuel or spark it is random when it is dry no issues. New plugs wires cap rotor fuel pump and filter. I am stumped.
Jan 23, 2020 at 8:02 PM
Advertisement
Avatar
ASEMASTER6371
  • CERTIFIED EXPERT
  • 52,796 POSTS
Good morning,

Are you still using the ECM? Without the O2 sensor, there is no signal from the exhaust for fuel control.

The MAP sensor may be the issue as it is dependent on atmospheric pressure.

Is the check engine light on?

Images (Click to enlarge)
Attached Media
Attached Media
Jan 24, 2020 at 5:27 AM