JDMCelsior

iTrader: (1)

Previous thread...
https://www.clublexus.com/forums/sho...d.php?t=300841

Just took the fuel pump out and tested it and long behold, it worked! I'm going clean out the relay that's in the engine fuse box and check power coming to the pump. The only problem I foresee is how to determine if its the main ECU or fuel pump ecu if there's no voltage at the pump??

I guess I can do what Grand LS4 did, jump started and see if it starts. If it starts, then is the ECU. If it doesn't start, then the FPECU is the problem. This is what happened to him and ended up being the MECU.

Any other pointers before I venture into unknown grounds will be greatly appreciated.

Ah, I'm also going to put the pump back after I clean the relay just to see if it starts, if not, I will proceed as planned.

Thanks for all the help!

sonyman

Well I'm glad it's not the pump. If it's the pump computer it will be a cheap fix if you source one used.

CptnTonus

Dude, seriously check the EFI fuse. It's located near the main relay. From what you're describing, it sounds like that's your culprit. I'd hate to see you drop a ton of cash on a new ECU when all you had to do was replace a $.30 fuse.

JDMCelsior

iTrader: (1)

I won't buy any ecu just yet, I actually took that silver EFI fuse out and kind of cleaned it. Tomorrow I will check the FP ECU and Main ECU. I will then interchange the silver fuses, put the pump back and try to start it. Of course, if I see there's no power coming to the M ECU to the FP ECU, then I'll know the Main ECU is bad. Either way, I will check. By the way, I checked for power going to the fuel pump and there was none.

JDMCelsior

iTrader: (1)

I swapped out the EFI fuse and still won't work. I'm just buying the damn ECU's and replace which ever is broke. I found one at the local yard, so tomorrow I'll be replacing one by one until the car starts. LOL


BTW, I can not find the fuel ECU. Where is it located? I've searched and really couldn't find exactly where the location is. any takers?

JDMCelsior

iTrader: (1)

I decided to put back the old pump back to test by passing the fuel ecu. I bridged b+ to FP (from the diagnostic plug under the hood); then proceeded to turn the key to the ON position. I immediately heard the pump humming so I cranked the car and thank GOD it started. I'm so glad it wasn't the ECU, so I'm on my way to the junk yard to buy a used FECU that works.

Thanks again for all the help/inputs.

LS400 for life!!!!

sonyman

I'm glad you've identified the problem. Good luck on your ECU hunt.