81 SD Fuel Problems

[imagesinthewind]

I looked at a car tonight that has a greasecar system installed.
It started right up and idled well and when it was up to temp it got switched to the VO and it purred. It seemed pretty decent.

We had to come back later to drive it.
The problem when driving was that it didn't have enough power to even keep it in 2nd gear. It stalled several times it seemed to have more power (though not real power) going downhill and lost power (I walk faster than we were going) uphill. We had the pedal to the floor and the car would get a bit faster and then lose it all.

We went out and bought new filters, both line and spin on, and it helped just a little. Maybe 10%. There was a small fuel leak that I seemed to fix by cranking down the primer pump. I doubt there was any real problem that was caused by the pump.

EDIT: The car has been sitting for 6 months and according to the owner drove fine last time her used it to make a round trip from Boulder to DIA (80 miles RT).
He seemed genuinely surprised and unhappy that it didn't run correctly.


What other fuel problems could there be?
Thanks!