Discussion:
Fuel Pressure PSI

Can someone send me the Fuel Pressure PSI range for a Hyster LPG Fuel System, GM 4.3L Engine WITH GFI under a load and without a load? I have already looked through the manual
  • Posted 9 Jul 2019 04:20
  • By c_globe
  • joined 9 Jul'19 - 3 messages
  • Virginia, United States
Showing items 1 - 6 of 6 results.
Anyone can help me Pls.
TOYOTA 7FGU45-BC
SERIAL 71695
Have problem accelerator not functions
Vtec vortex engine
Engine good but the accelerator is not functional potentiometer type
  • Posted 30 Jan 2020 14:42
  • By jonathan_l
  • joined 8 May'18 - 6 messages
  • Jeddah, Saudi Arabia
Im a hero
The serial number of the truck is: G004V05240J and it's a GFI fuel system with a wire harness connected to the LP regulator lock off.
  • Posted 10 Jul 2019 23:52
  • By c_globe
  • joined 9 Jul'19 - 3 messages
  • Virginia, United States
You did not give a serial number of the truck, and what type of LP system is on it
older trucks had the lock off filter unit and vaporizer
newer ones went to the EPR, and even that was evolved into a DEPR.

if your truck has a wire harness connected to the LP regulator (not a lock off solenoid harness but a multi-wire harness) then it has a EPR or DEPR system on it.

but based on the model you posted this under i found this

under testing and adjusting in service manual based on if this machine has an EPR or DEPR here are the pressure settings for these:
- EPR Primary Pressure: 13.8 to 27.6 kPa (2.0 to 4.0 psi)
- EPR Secondary Pressure (Engine idling with EPR electrical connector connected):
Water column or manometer measurement within ± 19 mm H2O (0.75 in. H2O) of PC Service Tool's "Actual Gaseous Fuel Pressure" value.
- EPR Secondary Pressure (Engine idling with EPR electrical connector disconnected): -25 to -76 mm H2O (-1.0 to -3.0 in. H2O)

- DEPR (PSI) Primary Pressure: 18+/-10 kPa (2.6 +/- 1.45 psi)
- DEPR (PSI) Secondary Pressure: 3.8+/-2.5 kPa (15.25 +/- 10 in. H2O)

If either of these apply to your machine you will need a PC Service tool to check it properly.
If you are not coding out chances are the EPR/DEPR is operating within it's parameters.

There were no other pressure settings listed for any other LP system for the GM 4.3L.

On older systems with the old type regulators they generally had a working pressure output of about 5 to 7 psi.
  • Posted 10 Jul 2019 09:46
  • By swoop223
  • joined 23 Mar'12 - 3,691 messages
  • North Carolina, United States
You've been swooped!
swoop223@gmail.com
That does not sound bad. Usually there are codes if the pressure is out of range. What problems are you having? We had one that ran rough. It had 2700 hours on it. We changed the injectors and the problem went away.
  • Posted 10 Jul 2019 00:19
  • Modified 10 Jul 2019 00:21 by poster
  • By BREWSKI
  • joined 10 Jan'12 - 1,699 messages
  • Nebraska, United States
It's not showing any codes. However, it is reading 10.5 under a load and sitting at idle it is 4.5.
  • Posted 10 Jul 2019 00:09
  • By c_globe
  • joined 9 Jul'19 - 3 messages
  • Virginia, United States
I never could find the spec on these. Are you throwing codes? Those injectors where known to cause problems if the got more than 2000 hours on them.
  • Posted 9 Jul 2019 23:31
  • By BREWSKI
  • joined 10 Jan'12 - 1,699 messages
  • Nebraska, United States

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