Outer Limits 4x4 Board

i think my sierra is using too much fuel. i run 31s and all i get is about 180km on the odometer per tank. sometines get bad fumes comming into the cab and engine doesnt like to rev. could this be a bad carb causing the probs?

I get about 435 Km per tank. Measured with GPS.

Make sure your choke isn't sticking on. Mine was chewing the fuel to, then I realised the choke was sticking on a bit, I wired it up (do it doesn't work at all) until I get time to fix it properly and its heaps better now.

How many litres of fuel?

I once had a Rockmod fuel tank that lost about 10litres cause of the shape it went

built4thrashing wrote:i think my sierra is using too much fuel. i run 31s and all i get is about 180km on the odometer per tank. sometines get bad fumes comming into the cab and engine doesnt like to rev. could this be a bad carb causing the probs?

i'm getting pretty much exactly the same as you too, and i'm on 31's as well. mine was worse before too, i've put a 91' ? carb on my 87' and it helped a little. the choke mechanism was different so i haven't got a choke at all right now. mine seems to be running rich though because the exhaust is always black with soot.

by the way, when i refill my tank it takes about 20-25 litres.

runnin 31s, get around 260 on the odo from a tank. usually 30-35L's when i fill up...

built4thrashing wrote:i think my sierra is using too much fuel. i run 31s and all i get is about 180km on the odometer per tank. sometines get bad fumes comming into the cab and engine doesnt like to rev. could this be a bad carb causing the probs?

clean your airfilter

when did you last clean/replace your fuel filters, mine was running badly with mud in the fuel, clean the float bowl out too.

You probably have the Sierra problem of having a massive dent in your fuel tank. A stock undented fuek tank will take 40 litres but even a mild looking dent can take as much as 10 litres from your capacity. Check to see how straight your tank is. I was able to get around 350 -380 kms from my tank but mine is nice and straight due to its lwb ute positioning, nice and high in the chassis just behind the cab in front of the rear axle

I've lost twenty litres to those crappy big dents in the bottom of my tank. I have the same problem with it running rich all the time and it also preignites (sp?) Found using premium helps alot. I have been told that my choke doesn't work either.

I fill up every fortnight if I don't go 4bying and drive to work which is a five minute drive. If I go offroad for a day trip I use about 3/4-1 tank.

have replaced carb with one from a 1.3 swift and it has improved a bit but is still running rich and backfiring on back off / engine braking.

i was getting 10 litres per 100kms
and thats with 260.000 on the clock. 32'' tyres & std r&p

check to see ur secondrys work
theres a small vacuum hose that goes from carby body to secondry diapham the hose swells from fuel/oil
if so replace & recheck secondrys work


check your catalytic converters not blocked or partly blocked
bash the catalytic converter with your hand see if it rattles
or disconnect flange n road test if it goes like the power of piss id say its the cat

my cat got so bad when i reved the zook the flange spings would compress & let the exhaust gasses exit the flange joint it sounded like a kettle boiling

where you live ?? if its near newy ill check it out for you
& tune her up .check secondrys & exhasut condition etc at no charge

ive also got a complete exhaust system if your cat is stuffed
you can have free. ive got to clear the garage need space
regards daryl

Any gears ??
With the 31's you've changed your gear ratios signifigantly (factory is 26) so th motor is working well out of it's rev range and also under load (like pulling a trailer all the time).

It's only a small motor so it notices changes in weights and loads alot.

have discovered some reason for the loss of fuel consumpotion (fuel tank will only hold 35 ltrs got a masive dent in it) but im still running rich. Tightened timing belt and checked tappits and now backfire is gone but i still have the fumes and the motor doesnt like to rev any higher than 5000rpm. Secondarys are opening but i run out of power at 5000. it will rev higher but there is no point. Will try to get a drive of another suzi to see how it runs.
I dont have extractors or a sports exhaust its all standard including intake