help please

[terrapin@halifax.com (animal)]

I just took my 78 scirocco out today after finally getting the 
radiator fan working again.
I though that was causing my overheating problems...and it probably 
was...but I now have a new problem.
It ran fine for the first 15 miles, but on a downhill, I let off the 
gas and it beganto sputter and the tach needle jumped up and down the 
dial.
As I came into town, when I pushed the clutch in, the tach would drop 
to less than 500 rpms immediately and then bounce as it idled rough.
Starting out, it would sputter up until 3,000 rpms and then it would 
take off like a scared rabbit.
But each gear shit would bring the same sputtering until it once 
again hit around 3,000 rpms.
Coming home and making the final turn, I pushed the clutch in and the 
engine died, but refired when I popped the clutch while it was still 
rolling.
Any suggestions on where to look.
I've blown and bunch of cash recently trying to get the fuel 
injection right and I think it is working properly, but this latest 
problem feels like it is fuel related.
Thanks for your help.
David Conner
terrapin@halifax.com
-- 
"Great spirits have always encountered violent opposition from mediocre minds."
-- Albert Einstein