A mild bit of MPG assistance please ;)

[Ben Lessani]

Hello guys,

So, on my quest for sorting my MPG, my last results averaged out to be 20MPG on Shell V-Power on a '86 K-Jet 1.8 8v. It still seems pretty low to me, so I was trying to find out the best way of finding out what might be off.

First things first was just to query the diagnostics on the MFA, as I don't have any readings to go off. I found these here (http://www.golfgtiforum.co.uk/index.php?topic=48159.msg379431#msg379431), but I don't know where its a 16v or not. My intake vacuum is 239 regardless of throttle position or how long the engine has been running.

Am I safe to assume that maybe I have a clogged air filter, or a vacuum leak?

The car has just been serviced and seems to be running alright, no flat spots or anything like that - just the MPG that's off.

Help my wallet guys, whats worth checking?

[mattkh]

Hi

A new air filter.

What tyre pressure are you using?

[monzablue16v]

the results are for an 8v on the link. I have a major fuel economy problem as well I get about 200 miles to a full tank on my 88 valver, does your MFA work on the mpg setting? mine doesn't and I think that might have something to do with it. I have tommorow to fiddle with it sounds like a similar problem.
My air filter is fine don't know about Blessani's!! tyre pressure about 35psi I bought the stuff to clean it with k&n air filter.

[Ben Lessani]

I've got a K&N (although not been cleaned for a long while - but saying that, the car hasn't been driven either), and the tyres are all at about 31 PSI - spot on really. I'll open the airbox today and take some snapshots

My MFA works to a certain extent, because I've had a tonne odd electrical oddities recently, I keep having to disconnect the battery, so the MFA keeps resetting. However, at the moment, on the AVG setting, my speed is usually off, 17 when doing mainly 30 (but I suppose it is average). My MPG is usually about 8. On the real time diagnostic settings, the MPG never stretches higher than 17, even on a downhill in fifth!

[Gambit]

for £10/11.5litres of sainsburys SUL i get about 65 mile which works out about 25.7 mile to the gallon.

and thats in & around town driving in a 16v

Monza u must have something seriously wrong!!! also, ur tyre pressures should be 32f/30r

[monzablue16v]

worked my mpg out to be 24.7 today need to find a long 3mm allen key as mine appears to have vanished somewhere Halfords don't do them any more bugger!!

[Ben Lessani]

whats the 3mm allen key for>

[monzablue16v]

It's to set the CO to 2% have you seen this link yet? link
I'm going to double check everything tuning and timing wise to see if that makes a difference if not I might just throw it at a garage and get them t find out why it is so bad on fuel economy also thinking of changing the fuel filter.

[VR6_ROB]

i can get about 70miles on 10quid driving steady away

my mfa shows 34MPG

[Ben Lessani]

right, ive just driven from glasgow to manchester 230 miles @ 65 mph (3:30 hrs), the fuel gauge only seems to have moved to just under 3/4 tank. So I'm ignoring that, when I fill up I will post my results Oh, I used BP Ultimate this time for comparison to Shell.