I had my sc400 in the shop over a year,and they gave up. Car starts but has no power like it's a bad catalytic converter. They said car wouldn't give a code and tried all they could think of. I'm going to storage next weekend to give this a shot. Ty brother! You've given me hope. I love that car!
@gbc9192 bet. I went out last weekend and tried this to no avail. This weekend I'm headed back out to the car.. I'll let ya know if it works. Think I'll do a full tune up on it if it looks like the wires are old or if they changed em at the mechanic. I can't remember.
That ecu also shutdowns the power to the fuel pump when the engine is not running. If in a accident and a fuel line is broken the pump will still pump fuel causing a spill and a potential fire hazard. I have mines bypassed but im going to go a different route by finding the other wire in the plug that only sends a signal while the engine is running and adding a relay.
Did you ever figure this out? My LS400 pump ECU I think is having issues as my car shut off twice, and if this makes this mod safer I'd like to do this also.
The relay provides power when the key is on. The FPCU distributes that power to the fuel pump under instruction from the ECU. The ECU waits to see the start signal and run the pump while cranking. If the ECU sees the engine is running, it continues to instruct the FPCU to run then pump in one of the two modes based on fuel demand. If the ECU sees the engine has stopped, like for example if there is a crash or a severed fuel line, it instructs the FPCU to stop the pump. This is an important safety feature.
Im not sure exactly what conditions the ECU needs to see to call for high or low speed mode, but its conceivable that if the low speed circuit works but the high speed circuit does not, the engine would cut out when there is high fuel demand. This would in turn reduce the demand for fuel and the ecu would call for low speed mode again, restoring fuel flow. You can troubleshoot this theory by connecting your test light to the FP terminal in the check connector port on your upper intake manifold. If this is the problem, you will see the light cut out under high load when the ecu calls for high speed and come back on again when it reverts to low speed.
What’s good brother I like I like you gave lots of game to help people step by step and this is my first time watching I love to learn more I have a few problems on mines if u have some time I really need your help I really appreciate it
I was just stuck in a parking lot mid day Florida and watched this video, tried it with a paper clip because it’s the best option I had and my car started. Did it work or was it perfect timing for the grimlin to hide? I’m not sure but thanks cause I’m going to say it was the paper clip along with the video.
many thanks for this Video I do the same for the gs 300 . but was problem with that which is , high pressure fuel result pump get hot and that's will short it life . many thanks Salem
So i did this same thing but jumped the wires by cutting them and soldered them together and then plugged the connector back into the fuel pump ecu. My main ecu got fried, could this be because I plugged the connector back in instead of leaving it out like in this video? Thank you for any help, this car is making me pull my hair out
My 1995 Lexus sc400 shut off on me while driving.. I did the ecu bypass and it still didn’t start. I never really had signs of a bad fuel pump but the most weird thing I would notice is when I take off my gas cap , it would make a sound of compressed air finally coming out like if my gas tank was thirsty for air lol. I’m about to change the fuel pump but I will be sad if it still doesn’t turn on lol. 155k on the dash
Brooo I have the same issue 😂 95 sc400 too I’m changing the fuel filter but it’s so rusted so I’m not sure if nothing works imma go take it to professional mechanic and diagnose it
As far air coming out of gas tank is due to charcoal canister is blocked . I have sc400 1993 happed same with me. Bypassed charcoal canister with cheap amazon filter worked for few days ( air stopped coming out of tank) but that filter failed. Now I’m back on factory charcoal canister which is 30 years old and definitely clogged.
What is the purpose of the emu if you can just bypass the plug? My Sc 400 ‘95 was starting fine - after I checked voltage on the engine bay Fuse box it will now not start: just cranks .... so would this be the Eli relay there. Thanks, H
That's a secondary function. The primary function is ensure the pump only runs if the engine is running... more specifically, in the event of a crash, it turns the pump off to prevent fuel being pumped onto the road - this is an important safety mechanism.
Not sure how you all feel about being burned alive, but it's not on my bucket list. The FPCU is responsible for TURNING OFF THE FUEL PUMP IN THE EVENT OF AN ACCIDENT. Without it, the contents of your fuel tank could be pumped out onto the road after a crash. There are aftermarket devices which monitor the ignition signal and can be used in conjunction with this mod, or at very least, a shock sensitive fuel cutoff switch from a Ford ranger should be installed in the circuit. The FPCU also keeps the fuel pump from turning on until the key hits the start position. With this mod, your fuel pump will run as long as your key is in the on position, including if your engine stalls, or (fatally for the fuel pump) if you run out of fuel.
@@GazaPerformanceGarageGPG I did . Problem is when the security light is blinking still when I insert the key, it won’t start because that disables the fuel pump . Will only crank but no start . I’ll just have to try this mod ! Thanks 🙏
Is this the same on the LS400? I have a 93 LS400 with 145k miles, and it's shut off in traffic twice. My LS400 has shut off on me twice now in really hot weather, I do plan to replace the cars ECU capacitors because I am starting to lose lighting in my RPM needle, and sometimes my RPM/Speedo do not work until I drive down the road for a few minutes. But I wonder aside from leaky capacitors in my cars ECU if this fuel pump ECU could be the cause for my car shutting off twice. What gauge wire did you use, or recommend for this also btw?
I did not see in your video how to jump the ECU completely you mentioned the red black and green wire but I could not see which wires you jumped together could you please explain which wires I am supposed to connect together I have the same problem
Hello how are you sorry about that you cut the black and red and the green off the plug then your going to crimp the two wires together with a wire connector. and thats it
when you bypass the ECU do do get like air leak coming from the injector when you put the key in the start position bc im getting air sound or its like fuel near the left side injector when engine is off and key in accessory position
This is because this mod makes your fuel pump run constantly as long as the key is in the on position... the FPCU prevented that previously. The sound you are hearing is likely fuel rushing through your fuel rails. The 1UZ uses a return fuel pressure regulator. This means that the pump pushes the fuel at, let's say upto 120 psi. The fuel flows into the left fuel rail at the fuel pressure damper, through to the fuel pressure regulator on the right rail. The fuel pressure regulator then bleeds off excess fuel pressure (over about 68 psi, if I recall correctly) through a return line back to the fuel tank. This means that fuel is constantly flowing through the fuel rails so long as the pump is running. This is only really a problem if there is a leak in the fuel system, like if you have a leaky injector or if you are in an accident.
I have a sc 400 and trying to get to to start I think this is the problem it's just cranks just doesn't fire but I don't ever hear the fuel pump kick on
My 1992 Lexus with 98k miles has a problem of not starting just cranking. I don’t hear the fuel pump kick on when I put the car in on position. Could this be the fuel pump itself or the fuel pump ECU?
First pull the gas tank lid and listen through the filler hole if there is noise or ir pushing out the means the pump is not getting power, then you do a fuel pump ecu bypass,make sure the fuel in the car is good because fuel can lose its luster and turn to oil only and will not start
@@GazaPerformanceGarageGPG I replaced the ecu fuel pump and it started right up. Then I want to say about 2 weeks later I let it sit for about 6 days and went to start it and boom! Won’t start again ! Can I use a paper clip to bypass the ecu I don’t have wire
@@GazaPerformanceGarageGPG okay so here is something else you may be able to help. After I unplugged the fuel pump ecu for about 5 Seconds then plug back in. The car franks and wants to die. I then crank again and it starts up no problem then will die again in a couple hours... thanks for the help !
Take a look at the video as well 8:00, connect the red and black wire to the green wire, cut the two wires from the clip and join them with a connector
So what I didn't ask you is if I bypass ecu is the fuel going to be regulated any or is it just going to be dumping large amounts & not ever stopping untill I cut the car off. This is my only ride.
@@shaunadapettway3890they only put the ecu to make the pump last an extra year longer and yes your fuel pressure is now full send for faster response more hp out put and I know your going to ask me why should I take this out if its making the fuel pump last longer" its up to you Shaundra. they dont make these any more and if you find one its going to cost you more than what a fuel pump cost and so on.... if you find one in the junk yard this is the reason why the car is in the junk yard and they could not figure why the car is not starting. so dont worry change it out and buy a walbro 255LPH pump for just 60 bucks for more Hp
@@GazaPerformanceGarageGPG Thanks for response. I hope I can do bypass and wait on that specific fuel pump because I do not have the funds for much extra.
Mine just died, For mine the car stalled (very softly). After driving and turning it off, I would try to restart it and it would just crank. Also morning startups were longer then usual. Then lastly one morning it would crank, start then die after 10 secs. I jumped two pins at the engine dio port and it started and ran. That told me my ecu was bad
@@skydyleyw0037 It is , got to test it out going to Naha today. Before I was getting a Code 34 DTC also, I was able to redline 1st to 3rd with no issues . Before it would take some time to start , now it starts within 2 seconds I would say. But I also ordered a AEM 320 to replace the stock pump .
Mr gaza i just got a 92 sc400 today… i got it from a seller in new york city and i drove it almost 2 hours to Long Island with no problem.. but when i stopped by for a fast food and turned off the engine it wont start anymore.. just endless cranking! i left the car and will comeback tomorrow.. any suggestions ❤️🙏 thanks
@@GazaPerformanceGarageGPG i did the bypass already sir’ thanks🙏 but sometimes the fuel pump still won’t kick in? I have to repeat several time and sometimes play around with the ignition until the fuel pump kicks in again and then it will start? Could it be the fuel pump dying out this time? When car runs its smooth… to be honest i like it better than my 97 SC300 manual✌️
@@rp17rionda if it has the original pump from 1992 yes change it, put the walbro 255PLH pump in also unplug the MAF and start it if that could be a problem. my friend what this boils down to is you have to do a full service on the car now. fuel pump, fuel filter, cap and rotor, spark plug and wires
I have ls400 93model I dont no 12v on fuel pump relay And no spark on plugs And no pluse on injector to Help will be highly apprectated😢 It cranks but not start
I have a video on something like that, I think it's the 2nd or 3rd video I made. But if you don't scan the car it could be a guess. There is also a video on how to scan your car if you don't have a ODBII port
@@GazaPerformanceGarageGPG check this out i just scanned the car with a jumper wire because obd1 and check engine just keeps flashing fast and doesn't stop lol smh wow it even let me diagnose codes ..
every almost every SC/LS enthusiast does this mod to save time because when it does go bad its hard to diagnose, im doing this for mine as well since mine went bad.
I did those trick but I just used a butt connector for the green and red wire and it ended up not working , and before it would start for a second and shit off , now it just cranks no start, anybody know why , thanks
of course mine wont start with this trick it just spins lol, maybe not getting good contact, ill probably just end up cutting them and splicing them directly together with a fuse in the middle
@@GazaPerformanceGarageGPG i recently got this 94 SC400 and im unaware if its had a fuel pump change, its at about 250k miles though so i suspect it might've been changed at one point
@@Cleavatr0n i was able to get it to work the way he did it, i just had to make the jumper shorter and use a thicker wire to get good contact, but ill deffinetly be permanently wiring it soon. i also just found out my SC400 is missfiring because the ECU needs rebuilt, it has some blown caps
@@spartanreaper911 I recently went through the same deal with the ECU. Kept throwing my car into limp mode and fucking everything up. I sent it to Tanin, got it rebuilt, and everything is good as new. I dunno what Toyota was thinking when they decided to make these things lol...
@@GazaPerformanceGarageGPG I m a bit confused. Javier said fuel pump ecu relay. Did he mean fuel pump ecu? Is there a fuel pump relay? Or is there just a EFI relay?
@@GazaPerformanceGarageGPG I drained my tank completely. Will the pump still start on an empty tank? I have 12v at the plug going into the sender unit.
fuel pump ecu went bad, they cost 400buck new and the ones you find in the junk yard no good. so you bypass and get 100% fuel pressure all time thus creating a faster throttle response. and more hp out put
