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80 series 4.5 petrol fuel economy

Posted: Wed Apr 18, 2007 12:42 pm
by evo wagon
ok guys i have a 4.5 twin cam petrol 80 gxl which when i got it, it had bad fuel economy. i opted to put a haltech e6x standalone ecu in it and had improved the fuel comsumption from 350kms to 90litres to 480kms. tuning was stopped at that point due to blown head gasket. So engine came out for full rebuild. once it went back on dyno and tuned we were getting 650kms round town and 750 on the high way which is a huge jump in economy as well as added horsepower.

any way point of this thread is when the car was on the dyno we noticed that we had a drive train issue as when you would back off into neutral the rear wheels would just come to a stop straight away wouldnt roll on like any other car and the car was a bitch to push round the workshop like the rear diff was locked. it had a lsd rear diff and the car has part time hubs fitted. so i think the rear diff was casuing the engine to chew more fuel then usual. i broke the rear diff and have a open centre fitted in it now and straight away found the car rolls with out any effort and picked up another 30hp on the dyno. the fuel economy is 850 to the tank now.

so it got me thinking all the other guys out there with the same fuel economy issue have you checked out your rear diff lsd maybe its too tight or on its way out casusing the bad fuel comsumption.
if it makes sense to anyone else your thoughts would be appriciated.

the reason for the huge fuel economay out of my car is because my tuner isnt afraid to take heaps off fuel out i also have bigger injectors.

Posted: Wed Apr 18, 2007 1:49 pm
by gtir300
Very interesting, I have never put my 80 on the rollers yet, I am curious to see how much it haas lost from new tho! It does chew some juice, but something I will look at when I get it dyno'd.

Posted: Wed Apr 18, 2007 2:20 pm
by physh
It'd probably do the same thing on a 100 series as well?
Maybe time to rip out the dodgy rear LSD and put twin air lockers in... :)

What else did you have done to the engine while it was out?
How much did the Haltech cost you, and was it hard to get installed right?

Also - where did you get it installed?
Anyone know of a place in Canberra I can get something similar done? :)


What size injectors you running?

I have a 100 series 1FZ-FE, got a unichip on at the moment but it sucks the fuel in a big way.
Constant 4wd, I get 109kw at all 4 wheels on petrol, 111kw on injected LPG.
I use approx 21.5L/100 of LPG on the highway, and about 18L/100 best on ULP.

Posted: Wed Apr 18, 2007 2:41 pm
by evo wagon
engine just had a stock rebuild and i have 660cc injectors in it.

buzz engines in qld supplied and fitted the haltech mates rates but i think the going rate is about 2100 fitted and tuned.

Posted: Wed Apr 18, 2007 4:51 pm
by RUFF
The '96 1FZFE Manual/full time 80 series i just totaled last Friday was getting an average of 16L-100K around town. Never got it out on a long trip though only had it for exactly 1 month. Had a trip to Newcastle planned for next weekend but Western QBE own it now and im flying down instead :D

Posted: Wed Apr 18, 2007 7:01 pm
by Mad Cruiser
RUFF wrote:The '96 1FZFE Manual/full time 80 series i just totaled last Friday was getting an average of 16L-100K around town. Never got it out on a long trip though only had it for exactly 1 month. Had a trip to Newcastle planned for next weekend but Western QBE own it now and im flying down instead :D
how'd u totaled it ?

Posted: Wed Apr 18, 2007 8:39 pm
by RUFF
Mad Cruiser wrote: how'd u totaled it ?
Side swiped by a truck and rolled over on the Gateway.

Posted: Wed Apr 18, 2007 9:27 pm
by tuf045
RUFF wrote:
Mad Cruiser wrote: how'd u totaled it ?
Side swiped by a truck and rolled over on the Gateway.
dam :cry: so what you buying next ;)

Posted: Thu Apr 19, 2007 7:27 am
by PGS 4WD
I can see how an LSD would use more fuel on the road around corners where the LSD is causing friction but on the dyno more power in a straight line dosent make sense, the LSD isn't doing anything on the dyno as both wheels are rotating at the same speed, its the same as an open wheeler diff in a straight line.. Perhaps there was something else wrong with the diff that caused it to break?? I've seen oils change HP figures(going from 140 to 90 weight etc), not by 30 hp, by 10 or so, as can tyres, and dyno operators by a lot more.
Joel

Posted: Thu Apr 19, 2007 9:27 am
by evo wagon
yer i think there was another problem with my diff causing the straight line drag but even in a straight line the think was hard to push and would not roll. but i thought i would share this with other 4.5 owners maybe it can help them out

Posted: Thu Apr 19, 2007 2:59 pm
by Mad Cruiser
RUFF wrote:
Mad Cruiser wrote: how'd u totaled it ?
Side swiped by a truck and rolled over on the Gateway.
U seem to have bad luck with cars mate..... Hope ya get another landcruiser :twisted:

Got any pics of the damage ? ;)

Posted: Thu Apr 19, 2007 6:31 pm
by RUFF
Mad Cruiser wrote:U seem to have bad luck with cars mate..... Hope ya get another landcruiser :twisted:

Got any pics of the damage ? ;)
Bad luck??? How do you figure that?

Will more than likely buy another 80 series. But im in no hurry. Will wait till a cheap one comes along again. No pics im going to post here sorry.

Posted: Thu Apr 19, 2007 11:12 pm
by PGS 4WD
I did the o2 sensor in mine and that helped, only good for series one though as was deleted in series 2. About $220 at Toyota.
Joel

Posted: Sun Jul 05, 2009 12:26 pm
by grub350
evo wagon wrote:engine just had a stock rebuild and i have 660cc injectors in it.

buzz engines in qld supplied and fitted the haltech mates rates but i think the going rate is about 2100 fitted and tuned.


hey mate i've got the 4.5 turboed and was just wondering wat model are the injectors and are they the same as any other motor?