1989 244 167K

I posted last week (click here to read that post*) that the mainpump on this car was noisy. I had replaced the intank pump last year (less than 3000 miles since then). I replaced the fuelpressure regulator in an effort to solve the noise problem and then today following the advice of the Brickboard I checked the return line for restriction. No restriction and the noise continued.

Further checking indicates the new intank pump has failed. Removing fuse #4 and applying 12v to the left side connector on 4 runs the mainpump as it should but 12v to the right side does not run the intank pump although it supplies the 12v to the connector in the trunk (12v on red/yellow wire). I tried adding an auxilary ground to the top of the sending unit (while supplying 12v to the intank pump +) and that didn't cause the pump to run either.

Question #1 Where does the intank pump get it ground?

Question#2 Based on the evidence does it appear the new intank pump has failed?

*the original post makes it sound like the prepump never worked based on the noise, that is not true; the noise started some time after the prepump replacement. 20/20 hindsight would indicate that was when the new pump failed. It is a ScanTech from FCP Groton; anybody else have a bad experience with these pumps?

Randy

Have you checked power to the tank pump at the 2 pin connector or the ground point at the tank cover plate? I have had at least 2 occasions where I also thought it was the pump and a check found 0v at the connector and a broken wire down stream...

Also you should be able to see a change in amp draw on the wire on turning the switch if the tamk pump is working

I have 12v to the connector (where the yellow/red wire connects to the black wire to the prepump). Looks pretty much like the relatively new intank pump has failed. I will double check continuity between the ground and the tank cover before opening things up. Thanks

Randy

two wires go to the pre pump, ofcourse one of them is grd. just trace it. Yes it sounds like pump failed, put in a AC one. I wonder about Scan Tech parts alot.

the ground is in the trunk, next to the access panel for the sender/pump assy. wanna check? pull the big inlet hose off the main pump, crank the car and see what you get out of that hose. use a clear jar, partially filled so you can see if it pumps, it pumps air, also. a blown hose in the tank will make a main pump noisy, also.

Thanks for the info. The intank pump is definitely not working. The hose was replaced at the same time the intank pump was and the noise is the same with a full tank when the fuel level would be above the hose level.

Randy