actually i didnt even do the jumper.. i just did a search on how to bypass the fuel ecu completely, connected those two wires together permanently, and my car runs fine now! no problems since i did this modification.. i would rather have 12volts going to the fuel pump all the time anyways..
that "fuel ecu" just looks like i big useless relay

if anyone wants to do this modification its pretty easy:
remove the rear side interior panel on the drivers side (remove back seats first)
find fuel ecu (its got 5 wires plugged into it)
cut and splice together the green wire and red/black wire (they are the biggest wires on the connector)
and youre done.. 12v going straight to the fuel pump all the time.

takes less than 20 minutes to do

 

If anyone needs a fuel ecu, I have one, can sell for 60 shipped.

Gazi

 

gotboost, be careful running the fuel pump @ 12v all the time. since it wasnt designed to run wide open all the time you might make it prone to failure. Good luck though.

 

This is a popular mod with MKIV TT Supras which have a similar fuel system to the SC/Soarer, they dont seem to suffer from any ill's doing this and remove the issue of having the TT run lean during the T1->T2 boost transition on modified engines.

 

oh thanks bill! i was considering the pump was made to run at a lower voltage and runing it hard all the time rather than at various time might hurt it. good to know it wont though (for my future reference). i gues they built them bulletproof as i would expect from lexus.

 

London Bill, you are my saviour I've just completed my 2jzgte swap, and was on my way to the office this morning, first real distance drive. Everything seemed ok on the ride in even with the heavy traffic. I parked the car in the parking garage, went out at lunch to take a customer out, and she wouldn't stay running.

Kept starting, but died right after. I then decided to listen for my newly installed walbro fuel pump, seeing that I can hear it pretty clearly. Turn the ignition on, nothing I then proceeded to go through all of the fuses, they all were ok.

Calmed down a bit, started surfing, and low an behold, I come to find out that the fuel pump ecu is a somewhat common failure. I then used your test to see if it was just the pump ecu, and used a paper clip to jump FP and +B. Turned the ignition on, and wouldn't you know it, I hear the pump go on.
I just ordered a new ecu today, not taking any chances with a used one. Hope to have it in the morning from McGrath Lexus.

Bill, thank you for your information, it saved my day!!!!

Chris
SC300TT

 

Better yet, I'm going to save myself the $200 for the new fuel pump ecu, and just do the 12v mod

 

Thanks for the feedback guys, I try to be the voice of calm reason (but sometimes I just flip, ain't that right PCMW?), in a world of misinformation and conjecture, it's good to hear that some benefit from this.

 

I told my Lexus mechanic of this spontaneous engine failure, and he told me it was most likely due to a voltage drop caused by faulty wiring (due to age and corrosion). A variance in +/-0.5 volts will cause the engine to shut off apparently. He said he's had other SCs come in for the same problem and he fixed it by replacing the ground wiring harness. Does this sound right?

 

Rich, I had that replaced on both my SC300 and SC400. Faults with those kind of pieces usually cause many random electrical ghosts until replaced. I had my SC300 for a few weeks before I did some replacement as a precaution. Neither car stalls. The SC400 was more problematic.

BTW I missed the mini-meet. When's the next one?