lexusseller

Has anyone encountered a very slow moving fuel gauge on their LS400. I have read all of the posts about blinking lights and bad needles and have none of those problems. This fuel gauge is definitely on its own schedule. Sometimes it will take 1/2 hour to get the needle moving and then it sometimes is still not reading right. I just went to Lexus and bought a new fuel sending unit. I took it to my mechanic and he plugged it in and grounded it and moved the float and the gauge did not react at all. He said it is in the gauge. Is this gauge part of the infamous motherboards or is it a seperate unit that can be replaced?
Any help would be appreciated.
Thanks in advance,
Richie

tn52

but it's too late I guess - I reported this problem a while back, bought and wasted $ on a new fuel sending unit without resolving the problem. Yes, it was part of the "famous" dash/electronic components. Eventually, the fuel gauge will not record anything at all so if you don't want to spend big $$$ on the dash unit, start to get used with the trip meter. It's a pain...

lexusseller

Does this mean I have to buy a whole new circuit board? Is the fuel gauge on its own board?
Thanks,
Richie

damon

I would love to find a solution to this for my 94. Currently , like TN 52 , I just use the trip meter

damon

tn52

I did not buy the fuel-dash component because, by itself alone, it was overprice (~ $650.00 part & labor). A lot of other dash cluster components (speedo, tach, lighting, etc...) will eventually go bad soon later so it makes sense to replace the whole cluster all together for the benefit of one time cost, convenience, & effort. I really think that these dash cluster problems happened due to defective designs/components and Lexus should do a recall on these. These problems are not isolate but very common with (at least) all first gen LS.

bigmon

Does anybody have the link to the instructions on this site to remove the fuel sending unit in the trunk? I've done a search and can't find it.

nthach

take out back seat, you will see the fuel tank and a plastic cover.

LexLS

I believe I have a fix for this, a tutorial will be coming soon. I will also probably sell the parts for the fix on my site, it should be cheap . My fuel guage is slow moving as well...

damon

"If your gauge is slow to react or stays on zero , the cap you need to focus on is C-142.
Value: 4.7 uf 25v.

pwgtang found this awhile back & I can verify that mine now works due to its replacement. He is an EE , so he knows his stuff".

all other cluster functions are original and still working fine.
94 LS
damon

https://www.clublexus.com/forums/sho...5&pagenumber=1

Long post but worth the read.

LexLS

90-92 Clusters are totally different than 93-94 clusters. We don't have a C142 cap. I have read the entire sticky post about this but unfortunately it mainly applies to 93-94 LS's. I think I've fixed the slow moving part of this problem for 90-92's...still testing though.

damon

Lexusseller has a 94 LS, does he not???

Keep up the excellent work on your site Earl. It is a great repair reference.

damon

PS: If I could solder at board level the repair would have been sub $10.00 dollars. I had to sub-contract so it cost me $75.00.

LexLS

Yeah, he should read that thread, you're right...long days damon, sorry I forgot he had a 94 . For 93-94 models the fix is in that thread....just recap the boards.

bn268

My 94 LS400 had the same fuel misreading problem,finally I had the problem fixed by LexusTech.com
The problem was in the printed circuit board.I was recommeded by a Mechanic at a Lexus dealership nearby my town.
I am quite happy with the work by Lexustech.com

vinegaroon

There is a man in Fresno, CA named Jim Walker who is fixing clusters of this vintage. His email is
jimlwalker@sbcglobal.com. He is also an EE and guarantees his work. I have sent him a cluster
with various problems including the sluggish fuel guage. He is still troubleshooting the source of
what causes the tach and speedo to refuse to come to life when the car starts, but he has fixed the
fuel guage problem. I am using a second cluster while he works on my primary one. This one also
has a slow, inaccurate fuel guage, but I'll guarantee he can fix those. I think he has a business link
on this site, but you can email him with your problems. If any of you know the source of what causes
those tach and speedo problems, please email him with your solutions.