Hi folks,

I get this cyclic moaning/vibrating sound (sounds like a complaining cow) that comes on whenever I am idling and it seems to be coming from the back of the car but I am not for certain. Noise disapears completly if the RPM's are above Idle even when sitting stationary. When the sound comes on and I am touching the Fuel Regulator, I feel a vibration at this location. Therefore the noise seems to be a part of the fuel deliv. sys.

Question: How would I diagnose if the pump in tank or on the chassis were bad or if the regulator that is bad causing the noise to start? PS Pulling off the vac line on the reg. shows no sign of leaking fuel.


Thanks in advance,

Tim

does your wife ride in the back by any chance.....sorry couldnt resist it...

Look at the top of this board. Features, down arrow. 700/900FAQs. Lots of info. Dead intank pump, car will run, but symptoms when less than 1/4 tank. Noisy main pump. Dead main pump, car won't run. My 85 has a separate fuse for the intank pump. Not sure about the 90. With car running, I pulled that fuse, definitely could hear the sound difference from the tank. But since the sound goes away with a little more gas. I would look for exhaust/muffler mounts, etc. Lots of tests for the noisy pump.

My ´93 has one fuse for each one of the two pumps and does the moaning if in-tank pump is not running. Wife´s ´95 has only one pump, so somwhere, for model ´94 or ´95 the setup was reduced to single pump config, I suspect it was for the ´95 model year.