Hilux to 1uz conversion fuel economy?

**urantia** · 31-10-2009, 01:59 PM

dunno if anyone has mentioned changing the ECU coolant temp sensor? If not, check that out too! apparently this sensor has the most influence on the ECU. Im changing mine today, cost me about $80 from toyota which was cheaper then i expected. But take a look here for more info:

http://www.clublexus.com/forums/ls40...read-this.html

**CrUZida** · 31-10-2009, 02:01 PM

Did you check yours to see if its outside of spec?

**urantia** · 31-10-2009, 02:13 PM

Nope, just gonna change it blindly like alot of other parts due to age of the car and general crummy looking condition of alot of sensors etc.

For anyone else tho prob, worth checking if your current coolant temp sensor is out of range, but from what im reading just about all of these coolant temp sensors get flakey with there readings to the ECU after 10 years.

Will report back with results if any.

**Cuzzo** · 31-10-2009, 03:18 PM

What resistance should it have?

**urantia** · 31-10-2009, 04:06 PM

http://www.clublexus.com/forums/atta...nsor-check.pdf

Depends on the coolant temp. But there is a nice graph in there to show the acceptable limits. Personally its easier for me to just install a new sensor instead of testing the old one, i figure the sensor has never been changed and my celsior bieng one of the earliest (1989) its probably well overdue.

**CrUZida** · 31-10-2009, 04:42 PM

I've checked a few coolant temp sensors over the years (including a 1UZ one and a 7MGTE one), and they've all been within spec.
Not saying that they don't fail, I just don't believe the '10 year' thing that others claim.

That said, its still definitely worth a check (btw, if you are checking from the ecu end, make sure you unplug the plug on the ecu that its on first, otherwise the reading will be wrong).

**urantia** · 31-10-2009, 06:52 PM

I think the "10 year" thing is more to do with crud buildup and scaly deposits (act as an insulator?) on the sensor causing them to read slightly different maybe? Well i know that was the case with a thermistor fan switch on my mums old camry.

**Shifty** · 29-04-2011, 03:53 PM

Kids, sorry to drag this up but it's better than starting a new thread

Just wondering if anyone has any more feedback on this topic as I'm looking at doing 1UZ/auto into an early Hilux which is quite a bit lighter than the norm - it should be a good few hundred kgs lighter than a Cressida, 4WD Hilux or even a later model 2WD Hilux.

**mullett** · 02-05-2011, 10:26 AM

As Cruzida mentioned, good economy is in the realm...my (fresh) conversion is getting 15L/100, probably due to the brand new generic O2 sensors which are putting out totally the wrong signal. Since it'll have an aftermarket ECU soon I'm not fussed about it, but I know of 4 other UZ conversions in 1300-1600kg cars, all getting 10-12l/100 in the city.