Registry 8x Series V8 Swaps

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Question for you guys. Who ran the fuel pump power wire to the Fuel Pump Resistor from the relay and who ran it directly to the fuel pump wire under the rear seat? I recently ran into this buzzing noise on the EFI Main Relay (90987-02004) in the cabin, near the foot pedals. The LC started but eventually stall.
After 30 mins of frustrations, I opened the panel and push the efi relay in, the loud buzzing noise became softer and then the LC started (someone mentioned if the EFI overheats in the What you do this weekend, the engine will stall). I ran the relay power wire to the fuel pump resistor. At home, I cut the power wire to the resistor and no more buzzing noise. My guess is a bad psi relay ground to the fuel relay (i'm using psi (@tmxmotorsports I know you dislike psi, :). Nice shop by the way and cool vintage vehicle. I temporary ran a new relay, fuse straight to the fuel pump and the buzzing noise has a faint sound now. I ordered two new efi relays, will swap out the one in the engine bay and in the cabin.

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@wiynwiyn I removed the factory fuel pump architecture and used the power from the ABS circuit and signal from the factory relay to a water proof relay. Then tapped directly into the fuel pump wire. It's fused and conveniently located. Almost 10k miles no issues.
 
wiynwiyn said:
Question for you guys. Who ran the fuel pump power wire to the Fuel Pump Resistor from the relay and who ran it directly to the fuel pump wire under the rear seat? I recently ran into this buzzing noise on the EFI Main Relay (90987-02004) in the cabin, near the foot pedals. The LC started but eventually stall.
After 30 mins of frustrations, I opened the panel and push the efi relay in, the loud buzzing noise became softer and then the LC started (someone mentioned if the EFI overheats in the What you do this weekend, the engine will stall). I ran the relay power wire to the fuel pump resistor. At home, I cut the power wire to the resistor and no more buzzing noise. My guess is a bad psi relay ground to the fuel relay (i'm using psi (@tmxmotorsports I know you dislike psi, :). Nice shop by the way and cool vintage vehicle. I temporary ran a new relay, fuse straight to the fuel pump and the buzzing noise has a faint sound now. I ordered two new efi relays, will swap out the one in the engine bay and in the cabin.

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What is the PSI relay?
 
NCtoyota said:
@wiynwiyn I removed the factory fuel pump architecture and used the power from the ABS circuit and signal from the factory relay to a water proof relay. Then tapped directly into the fuel pump wire. It's fused and conveniently located. Almost 10k miles no issues.
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Thanks for the info. Can you elaborate on removing the fuel pump architecture? Like unplug the connector to the fuel pump and run the positive wire to the fuel pump wire? Thanks
 
wiynwiyn said:
Thanks for the info. Can you elaborate on removing the fuel pump architecture? Like unplug the connector to the fuel pump and run the positive wire to the fuel pump wire? Thanks
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Removing the architecture may have been strong words, maybe did it for Dale could have been more appropriate. I stole power from the ABS circuit, 60A fuse (30) if I remember and robbed IG power (86) from the factory fuel pump relay. All tied into an aftermarket 4 pin relay using the body as a ground (85). I'm not sure if model years are different but it is a '94.

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wiynwiyn said:
Comes with the psi harness. I used their fuel relay.
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Is it there funky relay that looks like its a regular box style relay but it works differently and you can't just use a regular one. I have ran into this on a swapped jeep was an older psi harness. I don't use the 80 stuff just the wire going to the pump.
 
Thanks guys. I got this Fuel Pump Relay Kit. I like the idea of using a kit instead of tapping into the LC electrical, fear that might mess up something. The diagram is straight forward. If I were to run into any problems, easier to diagnose the issue and fix. I came across this video (how to wire a fuel pump). Maybe I have a voltage drop on the old system. Had a P2135 Thottle/pedal position sensor/switch a/b voltage correlation code when ran into the stalling issue. The LC fuel pump wire is 16 or 18 gauge. The wire size comes with the kit is 10 gauge ( LS swap fuel pump requires higher current and larger gauge wiring compared to typical carbureted or older fuel-injected setups), should prevent voltage drop. @NCtoyota Removing the architecture hurts my feeling a little, I'm an architect. hahaah

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I am traveling at the moment... So short

.Just add a relay after the Fuel Pump resistor..., bypassing everything before that resistor as well as the resistor itself

That relay controlled by the gm ecm.

This substantiality reduces wire path length...

I am using a 340lh aeromotive pump.
 
wiynwiyn said:
Thanks guys. I got this Fuel Pump Relay Kit. I like the idea of using a kit instead of tapping into the LC electrical, fear that might mess up something. The diagram is straight forward. If I were to run into any problems, easier to diagnose the issue and fix. I came across this video (how to wire a fuel pump). Maybe I have a voltage drop on the old system. Had a P2135 Thottle/pedal position sensor/switch a/b voltage correlation code when ran into the stalling issue. The LC fuel pump wire is 16 or 18 gauge. The wire size comes with the kit is 10 gauge ( LS swap fuel pump requires higher current and larger gauge wiring compared to typical carbureted or older fuel-injected setups), should prevent voltage drop. @NCtoyota Removing the architecture hurts my feeling a little, I'm an architect. hahaah

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I disagree with that diagram.

Don't use chassis ground to feed a 30 amp circuit. That's dumb.
 
I believe the Factory relays shut down the pump automatically if the engine stalls or a crash occurs. I wonder if I ran it like the diagram to the fuel pump directly and not to the fuel pump resistor. I fear the pump will run continuously, this is dangerous. Years back my friend's subaru got hit and within a few minutes the engine got ablaze, then the whole car caught on fire. Need to do more research. I think disconnecting the plug to the fuel pump and run the power wire to the pump is not a good idea.

A 1997 Toyota Land Cruiser (FZJ80) does not have a physical impact inertia switch or crash button. Instead, the safety system relies entirely on an electronic interlock loop managed by the Engine Control Unit (ECU) and the Circuit Opening Relay (COR).

If the truck is involved in an accident, the fuel pump cuts out instantly if the engine stops spinning, or if the airbag safety module commands a shutdown.

  • Loss of Crankshaft Signal (Engine Stalls): The engine ECU monitors the Crankshaft Position (NE) Sensor continuously. If a crash forces the vehicle to stall, engine RPM instantly drops to zero. As soon as the ECU loses the timing pulse from the spinning crankshaft, it cuts the grounding pathway to the Circuit Opening Relay. This immediately breaks the 12V power line supplying the fuel pump, turning it off in under a second.
  • SRS Airbag Module Interlock: The 1997 Land Cruiser features a factory Supplemental Restraint System (SRS). In a severe collision where the impact sensors trigger airbag deployment, a direct electronic signal communicates with the engine ECU. The ECU overrides all other inputs and shuts down the fuel pump circuit immediately to eliminate the threat of feeding a high-pressure line fire.
 
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Grab the fuel pump wire from where the factory fuel pump relay is at inside the driver inber fender well at the way towards the fire wall and bypass all the Toyota stuff hook the fuel pump wire from the psi harness to that. This is all you should need not another relay on top of the psi relay I think you might be confusing yourself its simple.
 
tmxmotorsports said:
Grab the fuel pump wire from where the factory fuel pump relay is at inside the driver inber fender well at the way towards the fire wall and bypass all the Toyota stuff hook the fuel pump wire from the psi harness to that. This is all you should need not another relay on top of the psi relay I think you might be confusing yourself its simple.
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Great idea. Appreciate it. Will run it to here so I won't have to remove the rear seats.

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tmxmotorsports said:
Grab the fuel pump wire from where the factory fuel pump relay is at inside the driver inber fender well at the way towards the fire wall and bypass all the Toyota stuff hook the fuel pump wire from the psi harness to that. This is all you should need not another relay on top of the psi relay I think you might be confusing yourself its simple.
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This.
 
Squad1 said:
looks great. I'm glad tat coldhose was able to help you out. I'm curious if yours makes any wierd noises inside the truck. I get a strange " wine" when the a/c is first turned on and then at random as it runs. It sounds to me like it might be the Freon flowing through the expansion valve, or to put it differently, like when you hear engine noise through your speaker. Almost sounds like when you get an ignition type noise picked up by a speaker. It is not electronic though, it's definitely a/c flow related. If I turn the a/c off it goes away. I am going to mess with reducing the Freon charge and see if it goes away. My a/c is very cold and works quite well. To date, no problem with the metric compression fittings where they compress onto the factory hard lines. Bloc, I too had a little trouble finding a place to crimp my lines, I took them to a friends shop and he let me use his hydraulic hose crimper. It worked fine, I just had to eyeball the amount of the crimp, as the dies were not an exact match to the a/c fittings.
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did you ever figure out the whining noise? i have the same thing. sounds just like an electrical whine through a head unit that increases with rpm. turn off A/C switch and stops.
 
Really think I have a bad ground, probably on the LC EFI main relay. I'll check the ground this weekend. Ordered two new efi relays as well.
I suppose to test it out for a bad ground; I can run a new ground wire to the efi main relay see if the buzzing/chattering goes away.
Also, will check ground of psi harness. FYi, engine started back up again after 30 mins, so something is causing the relay to overheat (bad ground or relay).
Once relay cooled down, engine fired up.

"A bad EFI main relay ground absolutely causes relay chatter. A poor ground limits the current needed for the electromagnetic coil, causing the internal contacts to vibrate rapidly (chatter) instead of closing fully, often resulting in stalling or hard starting."
 
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