chrisngo

iTrader: (1)

Hi all...i was fortunate enough to score a "dark blue" (indigo blue?) 1993 LS400 last nite! *pats self on back*

Well...the first problem I have is the fuel gauge. It is not accurate at all, it fluctuates between half and empty. I know the UCF10/11 have cluster problems...but from what i've read and searched, the only consistent cluster problem is the lighting . I have zero lighting issues.

I have read of some cap and transistor problems on the PCB from the MKIII Soarer guys in relation to the needles burning out. Could the fuel gauge accuracy be fixed with the replacement of a few SMC's?! I'm a recent EE grad...so I can probably tackle the soldering...but maybe not the troubleshooting just yet!

Well my question is....should i even be looking at the cluster as the culprit?! Should I be looking more towards the fuel cell and the sending unit?!

Thanks all!
Chris

Strida

Have you tried filling it up? Does it go to full? And when you drive does the fuel needle fluctuate erratically?

chrisngo

iTrader: (1)

Strida...

Yes it's been filled. Previous owner said that it never goes beyond the 3/4 mark.

I have noticed that the gauge will try to work it's way up when the engine gets warm, or after about 30 minutes of driving.

The fuel needle does not jump erattically. It kinda just stays in one place...right now I have about 1/4 tank, the needle is a bit below the 1/2 mark.

Thanks for the reply...any more suggestion would be great!
Chris

lexusk8

Just my opinion, I believe the fuel sensor of the LS is going bad and probably needs to be replaced.

rybikowsky

To isolate any problems from the area of the dashboard. You need to take a volt ohm meter and connect it to the sender leads on the gas tank. Sometimes if you can get someone to bounce the car up and down,while you watch meter readings you may see the meter change positions with the fuel level going up and down. This may not work if the sender is dampened.
If so have someone pour gas into the tank. Your meter reading should make a steady change if it does not, most likely the sender is going bad. This is a pretty easy fix, Good luck. carpe diem.

pwgtang

I post before, it was a bad capacitor on the computor board.

chrisngo

iTrader: (1)

Thank YOU!!!!!

I am going to buy the cap tomorrow. Hopefully it's the same problem!

For those interested here is the thread: https://www.clublexus.com/forums/sho...threadid=99264

THanks again...btw...have you found a job yet? I just recently found one. EE is a tough industry!

Chris

techlexus

90-92 LS400 do not have fuel guage problems, whereas the 93-94 LS do. the cluster board is slightly different from earlier models is that it utilizes a circuit controller for the guage. Reman of the cluster board fixes fuel guage problems. It is rarely the sender unit in tank. Mikado can reman the board at a very reasonable price.