As part of my rolling restore I put my fuel lines connections back on. I replaced the FI line from the fuel filter to the steel line that goes into the car and a few other lines. I hooked back up the fuel pump, hooked up the battery and turned the key. The fuel pump went on and after about 10 seconds turned off. I assume this is normal once the line reaches a certain pressure? I noticed some fuel was leaking from under the car. My question is what is how tight should I torque the FI clamps on the rubber lines where they connect to steel? I used a socket on a screw driver type wrench and tighten pretty good. Should I use a torque wrench on them?

No it is not normal for the fuel pump to turn on with the key, for a 124. The factory wiring is for the pump to run with the key in the start position and in the on position WITH THE ENGINE RUNNING. If it works as yours is doing then the PO or a previse "mechanic" has change the operation. I like the pump to run for a short time when you turn on the key to pressurize the system as yours does, but that is not how it was wired from the factory. As for the fuel line clamps, make sure you using fuel line clamps that seal all the way around and not just normal hose clamps. I just tighten mine up by hand with no problems.

redcars wrote:No it is not normal for the fuel pump to turn on with the key, for a 124. The factory wiring is for the pump to run with the key in the start position and in the on position WITH THE ENGINE RUNNING. If it works as yours is doing then the PO or a previse "mechanic" has change the operation. I like the pump to run for a short time when you turn on the key to pressurize the system as yours does, but that is not how it was wired from the factory. As for the fuel line clamps, make sure you using fuel line clamps that seal all the way around and not just normal hose clamps. I just tighten mine up by hand with no problems.

Yep. I put the white/black white and black ground on 1 terminal (this is the way it was wired before) and the (I think) green/black wire on the other terminal. Definitely runs with the key turned up 1 level (ie. car not on). The leak was one of the older steel lines that I probably over bent. Think I will cut out that section and replace with another FI rubber line section. The ones I already replaced with proper FI line clamps were fine.

I've read a bit and trying to understand the fuel pump wiring in my '81. Should only 2 wires go to the fuel pump (green/black and white/black for ground)? In my car there is another black wire bolted straight onto the body. Maybe this is why my fuel pump turns on when I turn the key up one click???

The extra black to the body would be a second ground which would not in any way cause you pump to run different other than it should.

redcars wrote:The extra black to the body would be a second ground which would not in any way cause you pump to run different other than it should.

So maybe the white/black ground line was having issues and the PO put an extra ground in. Just for kicks I'll try removing the extra ground and see if it still operates.

rjkoop wrote:

redcars wrote:The extra black to the body would be a second ground which would not in any way cause you pump to run different other than it should.

So maybe the white/black ground line was having issues and the PO put an extra ground in. Just for kicks I'll try removing the extra ground and see if it still operates.

Removed the 2nd ground and everything still works. So not sure why the PO did that. But I'd rather have it back to the original setup.