Doosan (& Daewoo) G25P-3:
Check Engine Light

Getting Code 73 and 74, We have replaced the fuel trim valve twice already replaced carb but still get these codes checked the O2 sensor according to the diagnostics and cant find anything that is giving the code any help would be greatly appreciated
  • Posted 2 Jul 2009 23:24
  • Discussion started by grant89
  • Minnesota, United States
Showing items 1 - 2 of 2 results.
check duty cycle, need laptop
  • Posted 26 May 2015 09:44
  • Reply by edward_m
  • Texas, United States
73=rich, 74=O2 sensor not switching because it stays high for extended time due to the over rich condition.
check vaporizer primary pressure, 2 - 3 psi.
check vacuum lines to and from trim valve for vacuum leaks, kinks, etc.
If mixer (carb) has been replaced as you state, the idle air has to be reset.
What color is the secondary diaphram in the vaporizer, if it is tan colored it has been known for heavy ends from fuel to bleed through diaphram then they get drawn into trim valve causing it to stick. Later diaphram is blue.
Also check the balance fitting at top of carb, should be an orfice not just a normal fitting.
  • Posted 7 Jul 2009 03:30
  • Modified 7 Jul 2009 03:31 by poster
  • Reply by carl_v
  • Pennsylvania, United States

Post your Reply

Forkliftaction.com accepts no responsibility for forum content and requires forum participants to adhere to the rules. Click here for more information.

Having trouble using the Discussion Forums? Contact us for help.

Latest job alerts …
Ottumwa, IA, United States
Harrisburg, SD, United States
Wentzville, MO, United States
Toplift Ferrari TFC36-48
Stoney Creek, Ontario, Canada
Used - Sale
USD1
Airman ENCL045
Yokohama, Japan
Used - Sale
Fact of the week
Bluetooth is named after the 10th-century Viking king, Harald Bluetooth, who united warring tribes in Denmark and Norway. In 1997, Jim Kardach from Intel gave the name to the technology because of its ability to unite different communication protocols, just as Harald united various tribes.

PREMIUM business

Noblelift
Global leader and manufacturer of high quality electric, lithium-ion, and IC material handling equipment.
Latest job alerts …
Harrisburg, SD, United States
Wentzville, MO, United States
Ottumwa, IA, United States
Upcoming in the editorial calendar
WIRELESS CHARGING
Aug 2025
MANAGING MIXED FLEETS
Oct 2025