sjwdavies

I’ve had my scooby back on the road (Jap Import 1995 WRX) now for a bout 3 weeks after having it stood for a couple of months. The car was fully serviced, including cam belt, a month or two before I stopped using it. I remember it being a thirsty car, but not this thirsty.

If I put £10 in, 99RON fuel @ 100.9p a litre, I get about 30 miles before it wants more juice. Surely there’s something wrong with the car? That works out to be about 15mpg???

I’ve been trying to drive it like a granddad cos we’re at the end of the month and I’m skint! Been driving it under 3000rpm with the occasional burst, but I think something’s definitely wrong.

The only thing I can think of is that the Bailey Dump Valve fitted is faulty. Sometimes it sticks open when the engine gets hot, and on the motorway between 70mph and 80mph it leaks boost – you can hear it.

Could this be causing the problem?

What can I do to try and improve mpg?

sjwdavies

The car's completely standard by the way, apart from a Kakimoto exhaust and the Bailey dump valve.

Marx Mcrae

iTrader: (4)

Bailey dump valves are actually rebuildable so why not just take it off and give it a good clean inside. Its not hard to do.

sjwdavies

Do you think it could be the dump valve then?

Jay m A

iTrader: (2)

it would be.

Metered air is escaping, hence its running rich

Stick tho OE one on and see how it goes

trails

iTrader: (41)

put the standard one back on and see how you get on...one less thing to worry about when isolating the issue

sjwdavies

Was gonna do that this afternoon...... I'll keep you updated. Cheers!

sjwdavies

Anything else you think it could be?

Green Classic 98

Could be that the cam belt is a tooth out?

sjwdavies

Really?

Is it easy to get that checked?

Boyakasha

iTrader: (2)

You need to fill the car up, zero the counter then drive it till the light comes on. Fill up again and tell us how many miles you got out of a tank and how many ltres you had to put in to fill it up again, then we will know your true mpg.

Doing it by sticking in £10 and thinking your getting 30 miles is a bit hit or miss.

Also ditch the dump valve, if you really want one then put a forge or HKS on.

sjwdavies

It's a classic, so no fuel light .

Also, off a tenner I get about 9.7 litres, so a gallon is 4.4 litres - so a tenner is roughly 2 gallons.

cster

How do you know if you have used all of the £10 of fuel up?
Unless you run it dry, you have no way of knowing.
The only way to know for sure (without running it dry) is to fill it to the brim, then drive it around and then fill it to the brim again.
Then you know accurately how much fuel is used.

trails

iTrader: (41)

its an EARLY classic so it doesn't have a fuel light

sjwdavies

You both have valid points.

But i've bin driving it till it's nearly empty - the point at which your frightened it's going to run out on you!

Trust me, i wouldn't get another 30 miles out of it.


I've just sawpped the dump valve over. Can anoyone tell me what the pipe is on the pictures below?

While replacing the dump valve, I noticed this pipe was seriously loose - so loose i could pull it out with ease. The clip holding it in was knackered. I've put a jubilee clip on it now so it's tight as a ducks ****.... but could this have been contributiong to fuel consumption? Does anone know what the pipe is?

demonsurfer

think it is a breather pipe fella

trails

iTrader: (41)

i think it goes to the boost solenoid...at least it does on a phase II engine!

Jay m A

iTrader: (2)

Its a breather and I doubt its the cause of your problem, still no harm in securing it

Dill_typeR

I doubt a VTA DV would cause this, overfuel, maybe, slightly, but only for the amount of air it has metered so it won't be over-compernsating.

Have you had your O2 sensor checked, if these go on any car it will use a lot of fuel.

I'm no expert btw

Hol

iTrader: (1)

You dont have to run your tank down to work out the mileage.

Go to the petrol station and fill it up until the pump cuts out.
Drive for XX-odd miles
Return to the same pump (if possible) and fill it up until it cuts out again.
Note the mileage and number of litres.

(No of miles/Divided by no of Litres) x 4.5 = MPG

[there are approx 4.5L per gallon]

EG.
(50miles/10L) x 4.5 = 22.5mpg.


Its maths innit!!!

Gear Head

iTrader: (2)

I was a bit confused?
Thought I had been doing it wrong all these years!

Tidgy

15mpg? get your foot flat on the floor lad, that'll get the figure down to the proper 10mpg lol

Boyakasha

iTrader: (2)

sjwdavies

ha ha ha

Tidgy

sorry couldn't resist

sjwdavies

Where can I goto get this checked? Is it something I can replace myself, is it expensive?

How can I get this checked out?

Are we talking about the Lamda sensor? Or the airflow sensor?

172sport

iTrader: (6)

I get between 150-190 per tank, 1995 wrx only mod is the exhaust 3" turbo back

totalllama

~270 Miles out of a full tank before the light comes on.
01 WRX wagon.

gti00eater

i get about 300 km per tank aprox 380bhp sti ra

silent running

LOL I thought it was just me that had a brain. Looks like there's two of us. I've never known why people are so obsessed with the 'light' coming on to tell you it's empty. I have a slight variation on what you do though.

I just fill the tank to the brim whenever I feel like it. I then reset the trip meter and whenever I feel like it, I go and brim it again. However many litres I bought, I divide by 4.5 to convert to gallons, keep that number in my head, then look at my trip meter. I take the trip meter mileage, divide it by the number of gallons stored in my head, and bingo there's my MPG. There's nothing more to it than that. I've usually done it all on my phone's calculator before I've even left the forecourt. I can tell even after only a quarter of a tank, whether I'm doing 25-26mpg 'cruising' economy or 20mpg 'caning it' economy. Running it all the way to the bottom of the tank won't have any advantage over doing shorter term checks at every fuel stop.