Wiring in driver's foot well causing trouble, what is there.

Hi all,

hopefully someone could give me some expert advise to understand the problem, please.

I got trouble with the wiring in the driver's foot well, RH-side (outer panel). I had stripped all the panelling away when I was chasing rust. The rust has been dealt with now, but that wiring is causing me trouble. I know cause while messing around with it I suddenly heard the fuel pump kick in. And I thought the pump had gone years ago !? (it would/will not run with less than quarter tank of petrol)

Next I tried starting the engine, it started then died instantly. No fuel I'd say. Tank is full, WD40 the wiring, messed with it more but nothing. Mind you its freezing here. Can that cause more trouble? Even now when turning the key the low oil and handbrake/caution light do not come on. Just the battery light. And still no start. (it does crank)

To understand the problem I got a few questions:

1- Can an engine start with fuel pump not working ? I thought it would, just not run well.
2- What other electrics run through that side panel. (besides door electrics)
3- Does the freeze make damp wiring worse ?

Many thanks for any suggestions,

Reg, Michael

Should add, that I suspect the sub-zero temperatures aggravating the problem and causing more trouble in damp wiring.

Is that right ?

Mike

"1- Can an engine start with fuel pump not working ? I thought it would, just not run well."

No, it can't. If the pump isn't working, then the fuel system can't pressurise and the engine stalls. In fact the procedure to de-pressurise the fuels system is to unplug the fuel pump relay, start the engine which will run for a few seconds then die when the pressure drops.

There is a lot of electrics down in that foot well - e.g. injector relay is next to fuel pump relay, which is below the main ECU.

Thanks Twinter,

That makes sense now.

As mentioned, I was under the impression my fuel pump did not work at all, because with a quarter tank left the car would only run idle. I now suspect the pump-output must have been less than normal (is that possible ?)

Probably changing the fuel pump and checking the wiring would solve the problem.

M

perhaps, have you changed the fuel filter recently?

Sorry Twinter, have been away for some time, but no have not changed the fuel filter. Yesterday done some work again. Finally it would start when, after fiddling with the wires, the fuel pump started working again. Then it suddenly cut out again, pump not working.

Tried more fiddling, but no luck. Changed relays around, no joy. Need to find out now which wiring leads to the pump and probably re-run it.

Unless someone else got a better idea ?


Mike

To update the situation,

Left the car overnight. Turned the key this morning to see if pump worked, nothing. Done the same this afternoon and the pump worked

Started the engine, it ran for a few minutes, then cut out again (pump stopped)

Would that indicate faulty relay anyway ?


Mike