Poor MPG

Hello!
This is my first post and I'm from Sweden so bear with me… I've recently bought my first car, a 1984 Jetta Mk1. I hope a Jetta is ok on this forum.
I bought it from a college so I know it has a good history. It?s in really good shape and I?m very pleased with it. The only downside is the poor mileage. My college got about 40 mpg, to and from work, 37 miles one way. I get 28 mpg to and from work, 13 miles one way. Sure, I do shorter trips but anyway. One morning it started to cut out at around 70 mph, it didn?t get enough fuel. I got a tip from a friend to blow in the fuel line from the tank. I did, and it felt like something in the fuel line loosened, it went from being very hard to blow in the hose to clean as a whistle. After that it ran perfectly. This was during my first tank of fuel so I have no idea about my mpg before that. Is it possible that I fixed the problem "too much". That the poor fuel line helped the mpg?

It is a Keihin 26/30 carburetor by the way.

the fuel line shouldn't make any difference. was your friend driving it very slow to get good mpg? it may just be different driving styles.

No, the speed is the same, between 60 and 70 mph. Actually, the 13 miles I drive to work is the same as his last 13 miles. We live along the same freeway, but he lives further away. I sometimes smell gasoline so I?m suspecting it is running rich. Think I?ll have to check my sparkplugs for signs. I have an Innovative wideband lambda in my other project, maybe I?ll borrow that for a while.

sounds like the mixture is wrong bud try a local garage to set it up on a comachine easy to do should be easy to cure also check for fuel leaks as there should be signs

Is it possible that wrong CO emission can affect the mixture? I thought that the CO screw only affected the mixture on idle??
(Thanks for the help so far…)

them vent covers look cool as, are they standard?? fabcy selling them??

I'm pretty sure it's standard. By the condition of the screws that holds it down you can tell that it's been there for a while…

What engine size have you got and is your right foot a little heavier than the last owners..

I'd be pleased to get 28mpg from any of mine, my MK2 stuggles to get 20 mpg and my GTi averages about 25-30..

hi i was getting poor mile a while ago got it checked out new dizzy rotor arm ht leads then it was fine i did not see the fuel gauge go down so fast before i done this yet it seemd to run ok except fuel consumpsion its ok now

It's a 1.6 engine with a Keihin 26/30 carburettor.
I don't think I have a heavy right foot, maybe a little.
Why I think it's runing rich is I sometimes smell fuel. And the sparkplugs are a bit sooty. I'll post som pictures later.

I think I've solved it now   . After filling upp the tank and parking on a dry place for a change, I noticed drops of fuel on the ground. It's been wet in Sweden for a month so that's why I haven't seen it before. The rubber hose between the fuelfiller pipe and the tank wasn't good. I've ordered a new one, fingers crossed.

Oh, the sparkplugs looks allright, right?

look fine to me you could get away with running a little bit leaner but not much. so i wouldn't worry about it.

wort checking the fuel filler neck they rust alot it leads to allsorts of probs. rust in tank

The fuel filler neck was replaced by the previous owner due to rust. I have some "rust shavings" in the tank, not much though. Only caused me trouble once, clogged the strainer in the tank. I blew in the fuel line and the problem was solved. When I emptied the tank to replace the hose between the tank and fuel filler I siphoned out as much rust as I could through the fuel sender hole under the back seat.

i done the same mate extended magnet works a treat the flexable type

V?lkomnande till Mk1 Golf ?gare Klubba , Jag hoppa det problemet med din bil ?r snart l?ste. JAG har den samma sak p? min Golf den v?nde ute till vara en l?cka i en r?r n?ra den f?rgasare. Hoppas den h?r Svensk ?r OK.