| Multiple mysteries, actually, all in one satisfying swoop. Many of you are familiar with the notorious whine of my fuel pump. I get asked all the time if it's been fixed yet. Several people have put forth theories about the cause. When I bought the car, that whine was already there. I replaced the fuel pump, thinking it might be about to go. The new pump was quiet for a couple days, then rapidly approached the noise level of the old; I pulled it out and re-installed the old one, not wanting to damage it if that was going to be an issue. Called the previous owner: "Oh yeah, it's been loud as long as I can remember." Stopped worrying that it was about to burn out. I switched out the fuel pump controller with a friend who had a '95 (like mine) - whine still there.
Switched out the ECU with his; whine still there.
Replaced the fuel pressure regulator, the fuel dampener, and the fuel filter; whine still there. So I measured the voltage coming to the pump and found it to be a constant 12v. Something was sending it the incorrect signal, but it wasn't any of the components. A little history: before I owned the car, it was smacked on the DS fender, powerfully enough to bend the tension rod and cause a need for a body weld in the engine bay that's clearly not factory over the wheel. Bernie came to the theory that the large body harness that runs through there got compromised by that accident and the solution would be found there. Several years ago we were in there and found an obvious crush point. We checked all the wires in that area, cleaned up anything that we could find, and re-wrapped the harness cleanly. At that point, we were chasing down a mysterious brown wire that was running by itself through the engine bay, replacing it and running it under the fender along the stock harness. Then, while addressing the turbo failure of last fall: "Do we know what this red wire is for?"
"Nope."
"Let's clip it and see what doesn't work." That one ran from the windshield wiper motor wires, down along the top of the trans bell housing and connected to some wiring back there. After getting the engine back in and the car back together, we started it up, only to find no reverse lights. Apparently that random wire was drawing power for them from the windshield wiper motor. Back to the present: last night while waiting in the garage for B, I stripped off all the tape and protective plastic tubing from that long stretch of body harness. The wiring in there looked pretty good and factory-wrapped, but I kept going anyway, determined to find, if nothing else, the cause of no reverse lights. Finally: 
You may notice the bent-back, sharp-edged bracket above those wire ends there. We checked the corrugated tubing where it had been on that section and found holes in it. Yep... We soldered those wires back together. One of them was brown; big surprise. We reunited it with its proper ends so it's now running with the rest, protected. 
Then, the moment of truth. Turned the key to the first position and put it in reverse: "We have lights!" Started the car. The parcel tray and the interior panel behind the seat are both out so the fuel tank area is unmuffled in any way. Quiet... Then the true test - blip the throttle, which was always when the voltage would shoot up and the whine would begin, constant until the car was shut off. ... Sweet, blessed silence.
You don't have to live in a bubble just because someone else caught the flu. Make your decision on your ability to trust yourself. - NytWolf 15:49:05 12/17/06
I was previously a aviation mechanic and avionic technician and this car is harder to work on than Aircraft. - Hocuz77 03:04:56 02/28/06 |
Mystery Solved. - 
