Good evening gentlemen. We've been running our car on jack stands to break in the new tremec and have come across a fuel pump problem we are trying to solve. We are running a new Mallory 140 pump and return regulator, Mallory 140 series fuel filter between the pump and tank, 1/2" lines and 6 psi of fuel pressure. When the car is cold, the pressure hovers around 6 psi +/- .5 or so. Then as the car is run for a while the fuel pressure slowly begins to drop. At about 180 degrees
oil temp, the fuel pressure drops to around 3 psi and at 210 degrees, the pressure drops off to nothing. Once it's hot, if I shut the pump off and turn it back on, the pressure 'jumps' to about 2 psi and then it quickly falls off to nothing again. The pump is wired with a relay and it's getting 12.2V.
This is the second pump we have had on the car. The original grenaded when it was first run and Mallory replaced it, recognizing they had a problem with QC on a recent batch of their pumps (this was back in 2000). This one has been sitting under the car for 2 years.
At first I thought the loss of pressure would be due to a drop in voltage, but that checks out okay. The pump is mounted by the tank and it's staying fairly cool, so excessive heat shouldn't be the cause either. Has anyone else had a problem with this with an electric pump? Tomorrow I will pull the filter out and check it, as I haven't done that yet and it's probably the first thing I should check.
Any opinions will be appreciated. Thanks!
Mike
Fuel pump problem (Mallory 140)?
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