I bought a K100 that has been sitting for 4 of 5 years. It turns over fine, but it's acting like the fuel pump is bad (understandably so!). 

I have a spare 87 fuel pump, but the electric plugs are different. Does anyone know where I could find a (fairly inexpensive) replacement fuel pump for my 85? Or perhaps there's a way to clean out the one I have?

Many thanks,
Nate

Here is a list of pumps that will do the job.


SUITABLE FOR:
HOLDEN Commodore VK EFI, VL turbo and non turbo, VN onwards V6 and V8 sedan wagon statesman
HOLDEN Camira JD JE Astra Calibra
FORD Falcon XE XF EFI
FERRARI 412i Coupe
NISSAN Skyline Pintara Pulsar Bluebird
 
ALFA ROMEO 33 Alfetta 75 90 GTV Spider
BMW M3 E30 M5 E28 318i 320i 323i 325e 325i 520i 525e 528i 535i 633Csi 635Csi 733i
CITROEN
FIAT Argenta Brava Regata Strada Ritmo X19
JAGUAR XJ6 XJs Sovereign
LANCIA Beta Delta Gamma Prisma Trevi Y10 Turbo
LOTUS Esprit Turbo
MASERATI Bi Turbo
MERCEDES-BENZ
MG Metro Turbo Maestro Montego
MITSUBISHI Colt Turbo Lancer
OPEL Ascona Corse Kadett Manta Monza Omega Rekord Vectra
PEUGEOT 205 309GTi 405 505
RENAULT R5 Turbo R11 Turbo R18 Turbo R19 R21 Turbo R25 Turbo Espace Quadra Fuego
ROVER SD1 Vitesse 3500 Vanden Plas RANGE ROVER LAND ROVER 3.5 & 3.9 EFI
SEAT Ibiza Malaga
VOLKSWAGEN Transporter Caravelle
Mapco 22301

Most fuel pumps will do the job but don't fit well. If you can remove the rubber vibration damper and replace with one for a 38-37mm pump and that lets you fit many pumps. The outlet and electrical connections are the important things to match up.

http://www.euromotoelectrics.com/category-s/753.htm His pumps are a bit pricey but are good quality as the rest of his stuff.

You're making the assumption that the fuel pump is bad but this may not be the case. No help can be given unless you describe the symptoms you're experiencing. All we can do is tell you where to get a pump. There have been a few similar threads here over the last few days. Go to the Portal page and look down the list of Latest Topics or use the search bar on that page to search for threads relating to pumps
If you get no joy from that, then come back and ask.
Let us know how you go.
Cheers