1UZ ECU - How specific are they to each engine/model - LS400/Celsior

[mullett]

And there you go, I thought only Nissans did that

[roadkill]

Hi,

after surfing the webzorz 4th surf, yours isn't the first instance of the coils being dead or close to it. I'm going to try and borrow some off of a mate hopefully tonight and see what comes of it.

bEn

[Sciflyer]

Interesting thread for me as i have an intermittant misfire under load/WOT that so far has not been cured by new leads, plugs, rotors, etc

ECU caps have been done, Fuel ECU bypassed, etc, all the usual checks

Luckily i have some spare coils so they are next to go in!

[roadkill]

Hi,

so i have run through the TPS diagnostics test and come up empty handed. At idle, i get 0.7v on VTA1, as throttle increases voltage increases to about 3.7. The idl circuit provides 0v at idle, and jumps to 9.0v when throttle is pressed in. Interestingly it does seem to take its time to get there ( a few seconds) which makes me think maybe a capacitor is charging? Dunno. From what i've read this should actually be about 12v... I have seen though taht the expected value is 9-14v. Little confused by this.

Ideas?


Also, tried a new pair of coils, no difference. Does anyone have a 93/94 ecu i can borrow??????

bEn

[4th surf]

Sorry bEn I've only got a spare '95 model ECU well that is when I can find where my wife has put the bloody thing. Try cleaning the TPS with some CRC electraclean as something isn't right there and it may be down to a simple clean and correct adjustment

[roadkill]

Hi,

yeah i know the feeling, that's just one of the many reasons i left my wife.

So far I've tried 3 different TPS's on, and exact same issue (each has a different part no too) I'm thinking i might take the ecu out and get the rest of the caps replaced, but i can't see that doing much to it.

There's about 18 of the 90-92 model ecu's on yahoo atm, and there is about the same amount of 95 onwards. You think i can find a friggin 93/94 anywhere but the states?!!?!?!?!? Being a LHD i don't know how well they'll work.....

bEn

[Sciflyer]

quick note: replaced one of the coils and the misfire is gone - yay!

[roadkill]

Hi,

lucky bugger. Mines still stuffing up. Got an ecu on the way Hopefully that fixes it. Otherwise, anyone wanna buy a lexus from me?

bEn

[dumbass]

Getting couple hundred bucks cash this weekend so I'll swap it for your ls400 hehehe
Then I'll fix it and sell it for more

Have u had a scanner on it at all to read live data
Or have u pulled ecu apart and looke dinside of it

[roadkill]

Hi,

haven't had a scanner on it yet but i bought a cheap one from the states, so that should be interesting to see how that goes. We pulled the ecu apart and replaced 3 of the caps as two were leaking and one had green feet, didn't replace the others tho yet, will probably do that in the next week or two. I've got another ecu on it's way too so hopefully we can see if it is the ecu or something else in the car.

bEn

[dumbass]

u need a scanner that will do the toyota half circular plug that sits
above the accelerator area

they are not obd2

[roadkill]

yeah i found an adaptor for obd1 to obd2 in the engine bay. Hopefully it works. Cost fark all so if it doesn't i won't be too concerned

[Hack]

Was surfing last night and found this on Lextreme

ECU:
Crown UZS131 - has two modules the ECU runs the engine and the ECT runs the transmission. The ECU is happy to run without the ECT
Crown UZS 141 & UZS151 – has single ECU/ECT and can be hard to run without the transmission or external sensors.
SC400 - uses single ECU/ECT.
LS400 - uses single ECU/ECT.
Celsior - uses single ECU/ECT.

Whilst the Crown UZS 141, UZS151, SC400, LS400 & Celsior use a combined ECU/ECT they are not interchangeable.

http://www.lextreme.com/1uzfe_variants.html

Hack

[dumbass]

crown 1uzs with two ecus are rare these days
most these days are single ecus
i did 4 1uz looms last month all were around 1995 celsior ones

[4th surf]

Some LS400/Celsior ECUs will interchange. I forget the exact model but is late UCF10/11 and it is a simple upgrade for the LS. 8/91 on I think where the Celsior runs a separate ECU for fan control (so no code 56) the rest while they may plug in won't run the engine.

I have a Crown loom and puter with the twin ECUs too