Water in my 1996 406 pls help!

[406owner2]

The pump only works when i push down the relay with the ign on, i did not here the usual "whistling" sound of 2 seconds, however perhaps it's due to the rail having enough fuel in it already and not needing to pump in more fuel, any way to test if the the rail has fuel inside it ?

I guess what i'll need to do is, have the ign on, manually press down the relay, while someone else cranks the engine, so i have the pump running while the engine cranks....

[lozz]

just start it up,
if it runs and then dies then theres a problem,

things like relays get moody when opened and messed with, so it may be fubard,

[steve_earwig]

Agreed, just try to start it, hopefully it'll fire and maybe run for a few seconds even if the relay is scrap. At least then we'll know.

[406owner2]

Thank you both.

I have to wait a bit for the little spill to dry anyway before i can try, is there a diagram or explanation on how the system works ie:

ignition on, ecu switches pump on, and check rail pressure.... ecu checks power to injectors.... etc.. etc..

I just need to know what the system does in sequence, so i can troubleshoot from there should the car not start.

I'm just thinking, what if the ecu is preventing the pump from turning on, because it did not receive an "on"signal from something else in the system ?

[406owner2]

Last post edited.

[lozz]

ign on relay opens fuelpump runs upto required preasure cuts off engine started ecu tells
all to carry on,

id presume im not auto sparky

[lozz]

if fuel pump don't run

then it can only be one of few things,

*Relay fubard, (*suspect as you've opened and messed with it)
*inertia cut off switch.
*imobiliser issue?

[406owner2]

Hi Lozz, the thing is just why have i not been hearing that 2-3 second sound that i always here prior to cranking. Then I suspect may/probably need a new relay, if the ecu is not deliberately preventing the relay from switching on the pump.

If it is the relay, i can simply manually push it down to start the petrol pump for that has worked in getting the pump going, the ecu as i understand it regulates the amount of fuel coming into the rails, however now if i interfere by leaving on the pump slightly longer by manually pushing down the relay, will it interfere with the ecu opening and closing the fuel going into the rail ?

Again i have yet to go and manually push in the relay and just try start the car however the above sums up what i've heard in the past prior to starting and what effect the relay might have if i manually push it down... that's just my thinking... i just have a bad feeling it might not start due to exactly what i described above, or something else we have not diagnosed yet...

[lozz]

Q:Again i have yet to go and manually push in the relay and just try start the car however the above sums up what i've heard in the past prior to starting and what effect the relay might have if i manually push it down... that's just my thinking... i just have a bad feeling it might not start due to exactly what i described above, or something else we have not diagnosed yet...


if theres fuel there it shouid start, but wont run long if the Relay is Fubar,

the relay being open whilst engine running shouidnt be aproblem just to test but longterm there might be issues of overfueling,

Have you not got any scrapyards/breakers nearby?.


see if car starts first, then chase whats needed,

[406owner2]

My thinking is (it may be wrong) what is the ecu doing with regards to letting fuel into the rail/engine, does it only switch the pump on and off as needed or does it in addition have some sort of a ecu operated valve closing and opening fuel into the rail/engine.

I'l get a new relay if that is the problem which seems to be it at this stage which i hope it is, i'm going down now, force that relay to start the pump, put in immob code and crank... lets see what happens...

[406owner2]

Ok, i cranked, first time it started sputtered, died, second time same, third time, started and the engine was on for 10 seconds sounded like it was on 2 cylinders, then died..... i have to go crank it more, but can anyone tell me, if i leave the pump on permanently , will it flood the rails/engine, it feels like it was the case, the last time i cranked when it ran for 10 seconds, with the pump, permanently running.

Does the ECU only control the inflow and outflow via switching the pump on and off,
i know the overflow sends back fuel, but still now that i'm manually controlling the pump it feels like i can flood the engine, is that possible ?

[406owner2]

updated last post.

[lozz]

as isaid above it may overfuel,


but you replied with (My thinking is (it may be wrong)



we are going round and round in circles here,

isaid earlier if it starts and runs then cuts out relay is fubar

what is your goal here? keep relay open so car runs and use as is


its your risk.. iwont coment any further,.

[406owner2]

ok, strange thing happened, the 2 second sound returned, i could swear the ign turned on that second relay for 2 seconds by itself, but again car starts only on for 4 seconds then dies....

[lozz]

get the multimeter out,

and Check that with the ignition on that you are getting 12 volts at pins on the relay module.

on the Peugeot 306's its pins 3 & 14 but ihavent got aclue if 406 is the same,