I've had a similar problem with my 90.
It quit on me a couple of weeks ago and I let it sit a few days. I went back a couple of days later, messed with the fuel pump(wiggled some wires) and it started right up. It drove fine for about 2 weeks then died on me as I was pulling into the parking lot.
After a little bit of troubleshooting.....I found there was no voltage to the pump, so I started testing the Fuel Pump Relay. I tried the pin 7 to pin 8 jumper. Wouldn't work. I did a voltage check to the female ends(jacks) of 7 and 8 and had nothing from either. I found jack 9 had voltage, so I put a jumper wire from pin 9 to 7 and 8 on the relay(providing voltage to both 7 & 8). Fuel pump worked perfect. Car ran fine....
I'm just worried that this could cause a problem, having the jumpers and all. The fuel pump only comes on when the key is on.
I'm pretty sure jack 7 or 8 should have voltage, but neither do. Would this be a problem with the connection to the relay base? I believe so...but I'm not sure. If it's not that, then it would have to be between the battery and the relay base. If anybody has any information on the wiring from the base to the batt, please let me know. Or any other tips for that matter.

Thanks