Decided to check the fuel pump operation.
 
I can confirm fuel pressure holds well within spec after the motor has been shut off (38 psi). Manual specs after 5min fuel pressure should be 21 psi or more. 
 
I followed the service manual for checking the fuel pump operation
 
- Connected the terminals +B and FP. Turned the ignition switch ON.
 
Fuel pressure showing 46 psi, (manual lists between 38-44 psi)
 
- Removed the SST (paper clip) and started the engine and disconnected the vacuum sensing hose from the fuel pressure regulator and plug the hose end.
 
Fuel pressure showing 46 psi (Manual lists between 38-44 psi)
 
- I reconnect the vacuum sensing hose to the fuel pressure regulator
 
Fuel pressure showing 46 psi (Manual lists between 30-37 psi)
 
- Ok now I'm thinking my regulator is not operating correctly. Doug is kind enough to take my phone calls and answer a few questions. I connect the vacuum line from the fuel regulator to an area that I know has vacuum. Start the engine.
 
Fuel pressure showing 38 psi (Manual lists between 30-37 psi)
 
- Confirmed the fuel pressure regulator is operational. So that means my vacuum lines may be connected incorrectly. I begin to check the manual again to find more information about the EFI system. The manual in the EFI schematic/description shows a VSV for fuel pressure and VSV for ACIS.
 
My car only has 1 VSV and it's between the vacuum tank and Actuator (VSV for ACIS?)...
Fuel pressure regulator vacuum line is connected to the main air intake hose T-piece. What has gone on here? I can't see any uplugged electrical connectors loose anywhere for a second VSV for fuel pressure.
 
Scratching my head at the moment.

Are you using the below 3sge manual? Looking at EG-234 it certainly describes a VSV being between the fuel reg and the vacuum source.
 
http://www.sq-engineering...kshop-manual-early.pdf

Mrskylighter
Are you using the below 3sge manual? Looking at EG-234 it certainly describes a VSV being between the fuel reg and the vacuum source.
http://www.sq-engineering...kshop-manual-early.pdf

Yep, that's the 3SGE manual I'm using. Page EG-163 shows the EFI system schematic too if your interested.
 
Labelled the vacuum hoses and snapped a quick photo under the car.
 

 

 

So the VSV (wherever it is hiding) is not functioning hence no vacuum being let through to the FPR. If you bypass the VSV connecting straight from the FPR to the inlet the pressure comes down?

Currently my fuel pressure reg isn't connected to a VSV. Fuel pressure reg vacuum line connects into the intake hose. But if I connect the fuel pressure reg to a different vacuum source the fuel pressure dropped to 38psi. The second photo shows the VSV (Green colour part) which is connected to the vacuum tank and actuator. The manual shows that there should be a second VSV mounted next to that one which the fuel pressure reg vacuum line should be connected into.
 
If someone with another later model Bathurst could check how their car is set up and post some photos for reference. I'm not sure if Toyota decided to make changes mid way though the production line and removed a VSV...

I doubt Toyota originally plumbed it like that. Some blighter has nicked yer VSV.
My 1998 Bathurst has 2 VSVs connected . One for fuel pressure regulator.
Should be an electrical connector hanging there somewhere ? Hiding.
You are welcome to come take a look at my car to find where its 2 connectors are in the harness.
Good work sussing it out so far. It certainly has ` Base ` fuel pressure constantly !

Roger confirmed his Bathurst only has 1 VSV... 
 
Can anyone else confirm the VSV and vacuum layout on their Bathurst?
 
 

This could also be an issue with dodgy capacitors in the ecu. A guy in Qld will replace all your capacitors and check the ecu over for $129 including postage back to you.

I found faulty capacitors in my gen3 3sgte ecu and have ordered replacements. Will attempt to change them out myself on my spare ecu. If it's too hard I'm going to pay for the service I mentioned.

This could describe your problem as when the caps are failing you get inconsistent issues. Even if the caps have not spewed their guts out and look fine they can still be bad.

Mrskylighter
This could also be an issue with dodgy capacitors in the ecu. A guy in Qld will replace all your capacitors and check the ecu over for $129 including postage back to you.

I found faulty capacitors in my gen3 3sgte ecu and have ordered replacements. Will attempt to change them out myself on my spare ecu. If it's too hard I'm going to pay for the service I mentioned.

This could describe your problem as when the caps are failing you get inconsistent issues. Even if the caps have not spewed their guts out and look fine they can still be bad.

Would you mind sending me a PM with his information?

I'll check mine tomorrow and let you know. I'm pretty sure mine only has one VSV too.

Sent from my SM-J320ZN using Tapatalk