Poor fuel economy in L series

rob83ke70 · Post by **rob83ke70** » Fri Jul 25, 2008 9:36 pm

Not 100% sure if this is the right place to ask this question, but here goes.

I have a 94 complianced ea82 caburettor powered L series sportswagon. No manifold vacuum leaks, oil changed religiously every 5 or 6 thousand km, before I owned it, every 12500km, clean filters, tyres pumped up to 32 psi (slightly bald though). Can of upper engine cleaner has been run through it about every 12500km since I've owned it. What sort of fuel economy should I be getting? It seems to chomp it horribly, around 15 litres/100km. The best I've every got it was about 9.5 litres/100km on the highway, most of the driving I do though is in town. I do Idle it for a few minutes with the auto choke on in the morning (its smegging cold here) before driving it 5 minutes to work, so it does get to operating temperature before I turn it off.

Is this normal sort of fuel consumption?

I was using about 20 litres/100km towing a trailer, but to be fair it was a HUGE trailer, possibly a bit big for the poor old subie... I think THAT was normal fuel consumption

discopotato03 · Post by **discopotato03** » Sat Jul 26, 2008 11:02 am

Cold running is a biggie particularly with carburettor choke systems .
I'd open the throttle slightly (by hand) and wriggle the carby's throttle shaft to check for wear - air leaks .

Late carby systems are a sea of pipework and the weight of it all must slow 90's L's down . The earlier ones were a lot less cluttered ... LOL .

I'd always keep the tyre pressures at 32 (check at running temp not cold) make sure it's wheel alignment (toe angles) are Ok and make sure you have no dragging brakes . If it has a points dizzy make sure the gap and dwell is within spec . Leads need to be acceptable .

Exhaust restrictions cost power and fuel .

A .

RetroLover · Post by **RetroLover** » Sat Jul 26, 2008 11:05 am

My first Subaru was a late gen Leone it had an EA82 engine but mine was Multi-Point-Fuel-Injected. In the last year of driving it the economy went to ****. When i first owned it, the best i got was something like 8 Liters per 100km but in the last year of owning it the economy went to the high teens. I was running my car on 98RON this fuel is lighter in density and obviously burns faster than 95 or 91.

But the cause i think of the poor fuel consumption in the EA82 engine was me probley pushing the engine too hard every time i took of and or the electricity supply in the car was low, not because of the battery was low but because of the Alternator dying. If the car is ideling a bit funny it could be the alternator.

littlewhiteute · Post by **littlewhiteute** » Sat Jul 26, 2008 7:16 pm

Cold start fast idling on the choke for a few minutes then 5 minute trip to work?
That will have a BIG adverse effect on fuel consumption.
Warming up is a old wives tale, you're better off moving off as soon as the engine feels a bit happy, and just be gentle for the first few kms.
At least the odometer is ticking over.

discopotato03 · Post by **discopotato03** » Sun Jul 27, 2008 8:36 am

Higher octane straight petrol has a higher specific gravity (therefore density) than lower octane stuff . It burns slower and is harder to light up than lower octane fuel . The value is in detonation resistance not burning efficiency so if the engines not detonation it's money down the drain .
Your call but if you can try 95-96 oct fuel you may be surprised , if you can try 95 octane E10 you may get an even bigger surprise .

A .

YouTube · Post by **El_Freddo** » Sun Jul 27, 2008 11:43 am

Also, further to what Disco has said, if you run a higer octane fuel you need to advance the timing for a carbie engine. The MPFI should handle an octane rating increase okay, but going from 91 RON to 98RON without timing adjustment may be a little too much for the MPFI ECU to advance timing to get the full potential out of the fuel.

As for the poor fuel consumption on the carbie L - the carbie may need an overhaul. I've seen a unit on a mates car that weeps fuel from a couple of the gaskets/seals. He hasn't had time to put a kit through it as he works in the snow, for now he just puts up with it...

Also check the compression on each cylinder, if its done quite a few k's, or medium k's with most of them being 5 minutes down the road the engine may just be a tired old unit that needs an overhaul. Short trips constantly will over a few years wear away an engine quicker than one that is taken on longer trips at full operating tempreture.

Cheers

Bennie

rob83ke70 · Post by **rob83ke70** » Sun Jul 27, 2008 3:10 pm

I'm pretty sure the carby isn't leaking fuel. I only warm it up enough to make it pull up the small hill on the road i live on ok, I don't warm it up too much idling with the choke on. I'm getting four new tyres and a wheel alignment very soon, and I'm thinking about the merits of putting a hotter spark plug in it (they were fouling at about 20000km, which I think is a result of driving to work with the choke on and cold engine). I'm running standard 6 or 8 degrees of timing with 91ron fuel, my timing light broke so I can't play around with it yet. I think I may advance the timing and put higher octane fuel in it. My alternator has a mad whine and I will be rebuilding that very soon too. I don't use the ac very much either.

I will keep an eye on it after I put the tyres on and get a wheel alignment, I'm about to start delivering pizza at night time in it, the car will feel loved again with me driving it a bit more often. I'm normally a motorcycle rider.

Might be worth me putting in on the gas analyser (after I fix the other cars mixtures up) at my new work.

rob83ke70 · Post by **rob83ke70** » Sun Aug 03, 2008 4:44 pm

i have four new road type tyres and a wheel alignment. i'm still using about 12lt per 100km, thinking about putting new plugs leads and an e type coil on. timing is set at 6 degrees last time i checked it, it was originally at about 10 or 12, i adjusted it back ages and ages ago when i was chasing other problems. the book said 6 so thats what i adjusted it to.

if i put 98 ron fuel in and advance the timing, would that make the total timing too far advanced? also, would i be better off running stock bp6e's or a heat range hotter? would the extended tip bp6ey plugs be better again?

didn't get a chance to put it on the gas analyser, i went chasing vacuum leaks in the toyota... what a job (rolls eyes).

rob83ke70 · Post by **rob83ke70** » Mon Aug 04, 2008 9:05 pm

put car on gas analyser at work this afternoon, found to be horribly lean, about 18:1 air/fuel ratio at idle, with idle a bit rough. hydrocarbons are very low along with very low carbon monoxide, which would indicate that my mixture is too lean, rather than having unmetered air entering engine. now to find out how to make it richer, whether i adjust the float, modify it somehow to obtain a mixture adjustment, or buy a weber dgv kit and fit it...

rob83ke70 · Post by **rob83ke70** » Sun Aug 10, 2008 3:13 pm

hey
would anyone have the idle screw out of an ea81 or ea82 carburettor, i'm assuming that its the same for either one. I have damaged mine when removing the "non adjustment" feature of it...

rob83ke70 · Post by **rob83ke70** » Wed Aug 13, 2008 10:37 pm

rebuilt the carburettor, everything was pretty old/gummed up. all is now clean, everything working correctly, and set idle mixture to 14.5:1 afr with the pulse air disconnected. seems to have miles more power, will see about fuel economy.

a weber would have been good, with a carb bonnet and a toyota hilux filter mounted on the drivers side front of the engine bay but it would have cost a lot more than the carby kit and probably taken a fair bit longer to set up... oh well, we will see how it goes.

Subafury · Post by **Subafury** » Thu Aug 14, 2008 1:33 am

ive got some pretty poor ecconomy happening. last week i got 300km to a tank with my ej22 L series. factor in the bigger tyres and ur looking at about 340km. pretty crap!

rob83ke70 · Post by **rob83ke70** » Sun Aug 17, 2008 12:33 pm

i've run half a tank of juice through the car so far, and it looks pretty dismal still. I set the mixture to around 14.5:1 at idle with the air injection disconnected, and the mixture seems all sweet, so i'm guessing i need to chase electrical things now. maybe hotter plugs? maybe a bigger coil? maybe vacuum advance and centrifugal advance?

maybe i should go right back to the beginning and do a compression test, the engine is 320,000km old, although its had a pretty good service history..........