Spitting and sputtering at speed, No power, ideas?

[Jettagli16v]

Hello, All!
I have been just lurking here for a few months,
cause both of my diesels have been running spot-on!

But now, I am back with a (hopefully)
slight issue.
Today on the way to work, the Golf was not running right.
1985 Golf NA Diesel, stock everything.

On the highway, I could not get up to speed
(she usually cruises at 75-85 Mph, with the tall gearbox)
and it would not get over 60. (and was losing speed up slight hills)
In the higher RPMs, it would spit and sputter a little bit,
(It feels just like the time I put a bottle of Lucas fuel additive appropriate for 25 gallons, into 2.
as soon as I filled the fuel tank, it got better.)
Also, this issue would come and go, it would clear up for just a second, and sound right, and then go back to sputtering.
It behaved the same way with the cold start handle in or out.

I know the fuel filter to be reasonably new, (a year or 2?)
and have had the same tank of fuel in it for 3 weeks or so.
No more smoke than usual, so I expect no air filter issues...

Any ideas?
Thanks!
-Brad

[maxfax]

A year (or 2) on a fuel filter is a good amount... That could be a good place to start..  Air leaks in the fuel line would be the next place to look...

[Jettagli16v]

Fuel lines are a bit old and tired.
I think I have some B100 compatible Viton-insert stuff left...

I shall start with new lines, new filter and a can of Diesel Purge, then?

As an aside,
It is a pretty (relatively) chilly day for Florida,
at a balmy 55F this morning..
Certainly rubber's elasticity is dependant on temperature...

-Brad

[Baron VonZeppelin]

I agree with Max's appraisal.

Fuel Filter #1.

You can get by with right much air, more than i would have thought anyway. But fresh hoses make for solid performance/delivery. Good investment doing them all on supply and return.

5/16" ID and 1/4" ID on mk2.

[Jettagli16v]

Very odd...
Left work Sunday, still sputtering a little,
topped off the fuel tank,
(Though I was not even yet in the red reserve)
and it drove perfectly the whole way home,
85Mph..

So I will still replace the fuel lines and filter just to know when the filter was done.

Hmmm.....
-Brad

[maxfax]

Maybe some funky fuel then..   New lines and filter never hurts though..   Save some future headaches..