s40 switching to petrol after 4 -5 minutes

[darrenain]

Newbie here, forgive any protocols missed.

can anyone help me out here, my 2001 s40 factory fit lpg system is switching to petrol after 4 or 5 minutes, if I turn off lpg and then back on again via the switch it will go back to petrol in a second or 2, if I switch the ignition off and restart it will run on lpg for 4 -5 minutes before going back to petrol, it is always the same amount of time, 4-5 minutes, never deviates.

I can confirm the tank solenoid and front one near the evaporator are switching and working??????

Scratching my head here, please help.

[darrenain]

REALLY CAN NOBODY HAVE A SINGLE IDEA AS TO WHAT THIS IS?

my 2001 s40 factory fit lpg system is switching to petrol after 4 or 5 minutes, if I turn off lpg and then back on again via the switch it will go back to petrol in a second or 2, if I switch the ignition off and restart it will run on lpg for 4 -5 minutes before going back to petrol, it is always the same amount of time, 4-5 minutes, never deviates.

I can confirm the tank solenoid and front one near the evaporator are switching and working??????

Scratching my head here, please help if you can

[reggit]

Have you got any fault codes?

[darrenain]

i have only just got this car so no fault codes, actually can you help with this, if i bought a cheap reader, do they work with s40 and ware do i plug em in and what connector is it, i must research this, but if you can help, thanks.

had a mishap, read somewhere that to much pressure can cause this, so i loosened the tank tank coil switching gear and let some gas out, in the process of this it blew out the 0 ring and so i had to run the gas out and take off the switch gear and replace the 0 ring, this is done and fixed, of course this released all the pressure in the tank etc etc.

now when i start the car, fine on petrol, when it switches to gas the car just stops, obviously not getting any gas, this a pressure issue?? if so haw to fix? or maybe is it air in the line because it been drained?? i dont know, if you can help here please do.

thanks for the reply reggit, hope you can help, like your vehicle line up.
i know the feeling.
i got myself
2001 volvo s40, 61,000
1972 mgb roadster, 20,000 yes you read that right.
2005 suzuki intruder m800 k5, 21,000
1982 suzuki gs850 chop, showing 1500 on new clock

[reggit]

Nice

2001 volvo s40, 61,000
1972 mgb roadster, 20,000 yes you read that right.
2005 suzuki intruder m800 k5, 21,000
1982 suzuki gs850 chop, showing 1500 on new clock

[/quote]


OK - from what little I know of the gas system.

If you've drained the gas lines, it will take a few goes to repressurise the front end, the engine just stalls - or at least mine did after I had it in bits.

On these, assuming the 40 is similar to the s60/V70, the gas distributor and stepper motor is the troublesome part of the system.

Can't advise on the cheap readers on the V40 as I don't know, on the S60 they will only retrieve the engine codes, but nothing else. It plugs into the OBD socket, which will be somewhere around the dashboard hidden away. looks to be on drivers side in centre console kick panel.

[darrenain]

thanks for the reply, turns out it was a sticking solenoid switch on the tank, fixed that, now back to original problem of switching to petrol after 4 -5 minuets.

its always the same amount of time, this must indicate something to someone, i cant be the only person ever to encounter this.

thanks for your help anyhow, i will get back if and when i have sussed it out, for anyone else suffering the same problem.

[darrenain]

been told it could be lambda / 02 sensor.

quick look at exhaust and iv got 3 sensors sticking out of it, 2 before the cat and 1 after.

which is which etc etc, i keep looking for a haynes or some such like but they dont cover bi fuel models, well cant find one anyhow. not happy, please help if you can.

[tainted]

Hi Darrenrain,

I have just had exactly the same fault develop on my s40 bifuel 2002, 155k miles on the Clock.

So far, based on other suggestions I have read it was the thermostat, changed that and that did not fix it!

I have looked all over the net and found no definitive answers, what have you turfed up?

Possible suggestions could be:

Coolant sensor faulty
Some sensor on the dizzy
Iffy stepper motor (doubtful)

Best and good luck!

Tainted

[tainted]

Forgot to add that to me it seems to be some sort of electrical fault.

I am hoping to borrow a code reader tomorrow.....