My car was with my mech. for 2 months as they tried to solve some fuel pump problems. Originally I replaced both pumps and the car failed to start though both pumps were working. I gave it to them and got it back a couple days later (said it was some bad connectors and a toasted dist. cap). When it came back there was a loud humming and vibration coming from under the hood and there was a large dead spot or miss that would occur regularly...so it went back the next day.

So I got the car back this week and it runs ok; the issues they discovered were in the wiring (fuel pump circuit...) and included some bad grounds. The whole system was checked (pressure), and they drove it around with a pressure gauge on it to see if it was fluctuating (no). 2 more new pumps were put in as the new main one I bought was making noise, they said.

There is still a loud humming and vibration under the hood and it is in the fuel line running down from the filter and I think there is still a miss or hesitation occurring, though much less dramatic. Mechanic thinks the rubber mounts holding the filter will solve this (no way), but if you grab the filter it does not diminish this abnormal vibe. I ordered a new accumulator to install as a different mechanic suggested it sounds like a "high frequency change in the fuel pressure" causing the vibes in the lines; not something caused by the pump. He also said he's never seen it though all his shop does is Volvo and he drives owns 2 '82 240s.

If anyone has seen this symptom (the vibrating fuel line) with this injection system I would be grateful to know the remedy. We've changed the warm up reg., the pumps and corrected wiring, new relays. There was originally resistance (heat) in the circuit to the pumps and that is no longer there.

Thanks.

Josh