gach2

I know treads have been started previously but I cannot find the information im after or in terms i Understand, my Apologies

My celsior/ls400 has been neglected in my garage the past 12 months due to other commitments and now wont start

Does start when sprayed with starter fluid but dies as soon its stopped

Fuel pump does not prime

EFI relay clicks but fuel relay does not click

Im lost on what or how to test from here on, any assistance would be appreciated

Thanks

Yamae

Sounds like the fuel pump relay is disabled by the circuit opening relay. The circuit opening relay stops the +B voltage supply to the fuel pump. This relay is triggered by the ECU when it detects serious 1 or more of these 4 different conditions and the fuel pump stops working.
1, No signal from the MAF for more than 3 seconds.
2, No signal from the crank position sensor for more than 5 seconds.
3, No signal from the cam position sensor for more than 5 seconds.
4, No IGF signal from the igniter for more than 3 seconds although the IGT signal is sent.

The link below may help you to know how the power is sent to the fuel pump although it's for a 98-00. Other generations are a bit different but mostly the same.
https://www.clublexus.com/forums/ls-...ml#post7719776

spuds

Yamae,could those issues you list be related to a long term dead battery then trying to start with a low battery after time? Just curious....Thanks.

gach2

Thanks Yamae
Also i have tried starting while brigding the b+ and fp on the diagnostic with no luck
I believe this would bypass the circuit opening relay or am I incorrect

The battery while now drained was 12v when attempting originally

Yamae

A long term dead battery sometimes causes strange problems. You can find the detail at below.
https://www.clublexus.com/forums/ls-...ml#post9338445

spuds

Just what I wanted to know.Thank you for the education,link bookmarked.

Yamae

Was the battery kept connecting while your car was in the garage for 12 months?
If so, there is a possibility that the ECU was malfunctioning caused by stray electrons due to the very slow voltage drop.

Moarpower

I had the same issue. I had a stuck circuit opening relay. Replaced it then found the fuel pump was dead.