2004 Bi-Fuel misfire and cutting out
 

Hi everyone!

New to this forum and was just wondering if anyone might be able to give me a bit of advise as to what to do with my 2004 S60 bifuel.

The main issue ive been getting is that the engine warning light comes on with an error code P0305 - cylinder 5 misfire/detected. this usually happens either when driving around 50-60mph with the car spluttering at these speeds or it can be at lower speeds under faster acceleration which also cause the message 'slow down or change gear'.

Whether or not releated, but the last couple of weeks the car has also started cutting out but luckily has only been at slow/low speed. Now these issues seem to be isolated to running on lpg and when it is driving on petrol, it drives smooth even at the 50-60mph speeds and havent seen any misfire detected.

From reading around i have replaced out the spark plugs to NGK BKR6ES and i have fitting a new coil pack to what i assume is cylinder 5 (im hoping its the one on the far right) but neither of these has made any difference

is there anything else that is worth trying that might solve these issues? my biggest concern is cutting out now as im a bit reluctant to drive it on lpg now

thanks for any help!

You may also try this test with the engine at idle, undo injectors (rather than coils) one by one, try see if any of them causes no idle change - this should rule out injector/coil/plug problem https://youtu.be/nDwtZCWU7u8

As for the 'slow down shift gear' message, I have a forum discussion that was pointing to the MAF sensor. Since it's expensive, may want to try a used one. If buying new, make sure to get the brand that makes the genuine ones (video on my channel how to remove the turbo one) https://www.matthewsvolvosite.com/fo...p?f=10&t=87918

Cheers i'll give it a try to see, currently it sounds like it idles pretty much the same on petrol as it does on LPG, just lpg presents an issue and reading with the obd its always same cylinder, going by the video its just a case of unplug each coil pack and if the idle does not drop, that coil could be faulty?

With the slow down/shift up and possibly pointing to MAF sensor, would you expect this issue to also happen on petrol or still just LPG, on petrol everything runs fine with no problems or warnings

If the idle doesn't drop, it can be either the coil, plug or injector. Usually the coil and possible the plug as well.

Not well up on the Volvo Bi-Fuel but LPG takes a stronger spark to ignite it than petrol so if there are any problems with the ignition, it will show up on LPG first and almost certainly be ok on petrol, at least for the time being.

Another thought, when was the LPG system last serviced? Heavy ends drained from the reducer, new filters etc?

i'll check the coils, plugs should be fine as fitted a new set a couple of days ago but i have only changed one coil on cylinder 5 which the error code said but made no difference

good question really as im not actually sure.. the car has had services and a main dealer one start of last year but couldnt say if the LPG had been serviced, what i have noticed is that when i fill up a full tank of lpg it only goes up 3/4 on the gauge and the gauge drops very quick when driving?

Doubt a main dealer would touch the LPG system....

Used to have an S60 bi-fuel, but I’m thinking back about 7 years now....

That used to cut out on LPG whenever a fault occurred, it should seamlessly switch back to petrol but never did. On mine it was a fault with the stepper motor, horrendously expensive little bugger! However it did log a code in Vida, something along the lines of ‘gaseous motor....’

I would expect the gauge to read full if you fill the tank, gauge will drop quite fast though as it’s only got a 200ish mile range on gas. Maybe it’s not filling to capacity? How much LPG does it take from empty to full?

Have you posted in the LPG section of this forum, there’s a very knowledgeable chap in there under the name of ‘CNGbifuel’

Might be worth getting the LPG system checked, not sure if your Volvo dealer will support it or whether you'll have to go to an LPG place.

When you fill with gas, do you hold the button until the pump stops or do you release it before it stops? If the latter, try holding it until the pump stops. If that doesn't bring the gauge up to full (they're notorious for sticking and unreliable readings on every LPG system) then you may need a new level sender but that isn't an easy job with gas in the tank! :nah:

Thanks for all the replies!

so for filling the tank, from empty it does put in i'll say full capacity till it shuts off which is about 45-50l? (cant remember off top of my head now) which gets about 230 range roughly when its all working 'fine'

the car has only been dealer serviced its life but i do wonder if the lpg has been touched atall in that time though! im use to lpgs though and not relying on the gauge so i keep more of an eye on the odometer, not the end of the world for the gauge to reading right (i hope)

for the times it has cut out, ive noticed the message 'switched to petrol' but at the same time it has 'stalled' which then takes a bit of persuation to get it started again (not so fun when youre blocking the road :baring_teeth:)

I had the same symptoms on my bifuel and that was the residue in the distributor. Swap the hose on the distributor and you will find misfire on the other cylinder. Remedy is remove the distributor and clean the bottom strainer and groves that go along the walls parallel to the stepmotor. Just be gentle