Car using too much petrol

[Spastik_Roach]

I'm sure my Sigma is using way too much petrol. Its 25 years old and automatic which doesn't help but it seems to really guzzle the stuff for just a 2.0l engine. Any tell-tale signs I can look for or things should I check for? Just a note its caburetted.

[Quiggs]

Is it running right, just using too much fuel? Check for vacuum leaks, make sure the screws on the carb are adjusted, clean/replace your air filter, fuel filter, spark plugs, wires, cap, rotor, yadda yadda yadda...

Check your tire pressures too. It'll all add up.

[clutch-monkey]

Originally Posted by Quiggs

Is it running right, just using too much fuel? Check for vacuum leaks, make sure the screws on the carb are adjusted, clean/replace your air filter, fuel filter, spark plugs, wires, cap, rotor, yadda yadda yadda...

Check your tire pressures too. It'll all add up.

what he said. tune up + service might be needed

edit: unless you're fatter than before

[whiteballz]

how many kays per tank are you getting?

[pimento]

Sounds like your car has a problem.. an addiction to overusing fuel. I would suggest setting up an intervention, maybe even calling in a professional to try and get through to the root of your car's problem. It can be hard, but in the long run it's best to get these things out into the open.

Or.. you know.. check compression, clean the carbie, make sure the fuel mixture is right.. old slushy autos are pretty poor for fuel usage on take-off, so you could also experiment with driving like a little old lady and seeing what kind of difference that makes.

[f6fhellcat13]

are you sure you dont have a small toad or dwarf in your tank? I suggest bleeding with leeches.

[#1 Mustang Fan]

As said before, its probably a number of little things adding up, I know wheel alignment can be a bitch.

Maybe just a quick check up with the local or something should help. But beforehand check around with things previously mentioned and you might find you have a few screws out of place.

[Spastik_Roach]

Brand new air filter so thats no probs. Tire's need air I think so I'll get that done a.s.a.p. Its running fine otherwise, no problems. Dunno how many km per tank I'm getting cause I haven't been driving it on account of me not having my license yet (two weeks to go till I do!) I'll check the carb tomorrow.
One thing my mate pointed out to me is that his car lasts ages from a full tank to half full but seems to go from half full to empty really quickly. My car never has over half a tank full since I've had it so that could be something. Could be utter bullshit aswell but meh. Its going in for a warrant of fitness on Wednesday so I'll ask the mechanics to give it a look at.

[clutch-monkey]

Originally Posted by Spastik_Roach

One thing my mate pointed out to me is that his car lasts ages from a full tank to half full but seems to go from half full to empty really quickly.

lol might be psychological, that...
silly question but is it meant to use leaded or unleaded?
either way, engine swap time

[Spastik_Roach]

Originally Posted by clutch-monkey

lol might be psychological, that...
silly question but is it meant to use leaded or unleaded?
either way, engine swap time

I'm pretty sure its fine on unleaded. Nana's always put unleaded in I think and she asked a mechanic about what petrol to put in. She's always used 98 but I'm just putting in 91 myself.

I've noticed that too in his car. We made about a 300km trip once on a full tank and it barely went down a quarter. Made a 400 km trip on just over a half tank and it was near empty at the end of that. 300km trip had 3 more people in the car too. I'm certain theres a difference there!

and compared to whatever engines I'd wanna swap in this'd be better than a Prius!

[pimento]

Maybe your mate's fuel guage is dodgy.. The old BMW I used to drive had both a dodgy gauge that was always reading low, and a gauge that changed scale as it went up.. it was a 55 litre tank, but the mid-point on the gauge was at about 20 litres.

[Spastik_Roach]

I don't wanna find that one out the hard way!

[fpv_gtho]

Its pretty common to have the top half of the gauge bigger than the bottom half. Mums Camry has it and my Pulsar certainly does - i once got 300km and it was reading just under half, but before i could get 400km it didnt want to stay above a quarter tank.

Without knowing how much youre getting per tank, or even L/100km would be better, its hard to say if theres even a problem. I'd be surprised if a 25yo 2L 4cyl carby fed autos (3 speed?) used less than 12-13L/100km

[henk4]

I have never ever seen a fully linear tank gauge. They are always "optimistic" on the right hand side and speed up greatly once past the middle of the scale.....However one should realise that you never completely drain the tank, so in reality the difference might not so great as subjectively felt.

[charged]

Are you driving it harder ? that can make a huge difference, also the the 2 litre astron running a 3 speed slushbox wont be the most fuel efficient 4cylinder going around. As FPV said whats the litres/100 per hundred ?


If its heavier than normal a tune may be needed, plugs, points, air cleaner etc.