engine splutters when changing from petrol to gas

[danny123]

last few days started to have problem with the stag lpg. when it reaches it temp 50 degress it changes form petrol to gas which is normal ,but splutters when i press the accelerater pedal ,but if i drive it for a bit to get the engine hot its fine ,any ideas please

[rossko]

Thinks: last few days have been colder. Which way up are your injectors, full of goop perhaps?

[Dai Fish]

Mine has been doing this the last few days to Ross, I just put it back on to petrol for an extra couple of miles then it's right as rain again, as you have seen my injectors are stood up the correct way etc

Dai

[danny123]

the injectors lie flat on the engine ,but the lpg dont kick in till the engine temp of 55 degrees.thought that would be hot enough to be fair

[mat_fenwick]

It's not necessarily water temperature, but injector temperature - in a colder ambient they will take longer to get up to a temperature where any gloop will be liquid enough to flow.

[hardcorepit80]

All you have to do is TEMPERATURE CORRECTION

[danny123]

so its quite common then in the colder weather is there away i could stop this at all,as my mate has the ssame system stag6 plus but does not have the problem

[mat_fenwick]

All you have to do is TEMPERATURE CORRECTION

Isn't that making the assumption that the problem is down to unwanted petrol enrichment during the warm up period?

[hardcorepit80]

All you have to do is TEMPERATURE CORRECTION

Isn't that making the assumption that the problem is down to unwanted petrol enrichment during the warm up period?

To deal with "unwanted enrichment" in VAG cars there's Tab called "cold engine leaning"
I meant proper gas temperature correction.

Just follow instructions and make nice temp. correction and then if the problem is still there, play with settings in "cold engine leaning" "Advance" tab

[danny123]

took the car to autogas west bromwich changed the temp sensor on the vaporiser great know

[danny123]

not so great still the same

[Absenthe]

Danny any information on the problem yet, I too have the same problem, I have sent the PS02 back to retailer and have correct readings now, the old one was giving me readings of Gas Temp 30-40 deg when cold! the correct readings are now being given but the system is giving me gas on reducer Temp change over 50 Deg not - Gas temp sensor Change over set to 29 Deg min.

Before the problem started the unit would give the System gas upto the Rail when Temp of 50 was reached, but would never give it gas until Gas Temp was at 29 Deg.

Now the retailer is telling me the unit is fine and that the Gas Temp is only to ensure the Reducer does not freeze, if thats the case why was my Faulty PS02 that I sent back giving me readings of 30-40 deg when cold? I believe there is a Fault in the GAS ECU but retailer says no, she said my Old Temp Sensor works fine in her car? Why is it in her car, and why is the faulty unit not sent back to AC STAG?

She has informed me to go back to factory settings and start from fresh, will do that this weekend and report the problems to AC Stag first and the retailer second.

Anyway any info you could supply me with would be great.

Regards

Phil

[danny123]

went back to autogas they altered the change over to 65 degree from petrol to gas ,started the car up still the same .they said the weather can course the problem. cant see how the weather would effect it as its not that cold yet

[Absenthe]

Danny what car do you have it on again and how long have you run it on Gas?

I will be looking into mine tomorrow and setting it back to factory settings and adjusting it to suit, I hope and pray that will solve the problem, I will report back the details.

Regards

Phil

went back to autogas they altered the change over to 65 degree from petrol to gas ,started the car up still the same .they said the weather can course the problem. cant see how the weather would effect it as its not that cold yet

[rossko]

Observe the gas pressure at the time of first switchover, is it unreasonably low or high.

Observe the car's lambda sensor before changeover, is it working normally, what does it do at the point of switchover.

Run on gas, switch to petrol and allow to idle for ten minutes - monitor the gas pressure during this time for seeps in or out.

If your Stag has injector pre-heating options, try them out.

Try un-checking sequential changeover options in case of wiring error.

[danny123]

to be honest mate not that clued up on it that much ,ill have to take it to the garage again,is anyone local to birmingham that could be recommeneded thanks

[danny123]

have had the switch over temp changed to 70 degrees its still the same ,it seems that when the car left over night it only happens when the engine is stone cold ,when i start it up in the morning get the car to temperture then leave it for a may be a few hours then start it up again its fine no problems ,

[Absenthe]

Danny I have not had chance to look at mine yet due to work, but as ross says,

it might be worth checking the injector pre heating and I may look at the Temp correction as told to me by another Gas fitter on the Forum.

[hardcorepit80]

Absenthe,danny123 Please record osc. file from running from cold until switch over, if that possible, and post it.
Then we can see what's going on.

[classicswede]

To me it sounds like classic gloop in the injectors. Once they have freed up then are fine untill they fully cool down again. I would give them a good clean up before things get any worse.

Using injector heating is only likely to bake the gunk onto the injectors making things worse long term.