Timing? = '89 100

[jDolan]

I've been asked to sort out a 1989 model 100 that is running poorly.
The idle was ranging widely, and it had no "oompfh." I found a bad vacuum
hose, cleaned the ISV and went over all the obvious things: grounds, wires,
etc., and it now idles in the range of 1000 rpm's, but does tend to "hunt" a
bit. It still is a bit sluggish, and I suspect part of the problem is the
cat bing stuffed up.
 My main questions/considerations are: When the vehicle came to me, it had a
fuse in place in the fuel pump relay, and it was being driven that way. When
the fuse is removed, the idle ascends to the range of 2000 rpm's. I'm
thinking that the vehicle was timed/setup with this fuse there. Should I
just remove it and re-time the motor? Is there a recommended website that
might have particulars as to how to do this? I don't have a Bentley's. If
anyone wants to offer advice, I'd certainly and welcomely receive it.
And finally, would sustained operation with that fuse in place permanently
damage anything? I have no idea how long it has been there.
 Thanks for any help offered.

jim   '88 90q  w/263K miles.
Rochester, Vt.
Rover car for sale: http://www.sover.net/~jhdolan/p5%20page.htm