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[andy.]

Hello, just joined the forum tonight and wondered if anyone has experience of the problem i am having and is able to offer any guidence thanks... A couple of months ago i brought a 1997 `R reg 2.5 v6 omega reflection which had only had one owner from new and 40k . After driving the car for a few months and enjoying trouble free motoring i had an opertunity to swap a fully functional prinz lpg conversion of a friends 98`s reg 2.5 cdx which he was saying goodbye to on the scrappage scheme,so along with the full leather interior, i swapped the conversion over. On petrol the car runs fine. however on lpg the car is ok, maybe very slightly lumpy at tick over and if you don`t load the engine and rev it gentley it will rise through the rev range smoothly, likewise whilst driving at a set speed on the flat you can swap to gas and make smooth progress for miles.the problem comes when it is revved hard stationary or is accellerated on the road whilst on lpg, even very gentle accelleration and it misfires awfull , swap back to petrol for an immediate cure. Firstly thinking lpg would need a stronger spark i have replaced the plugs with twin electrode ngk as recommended they came out clean and oil free and a set of delco ht leads,(and a new egr gasket after breaking the old one!),no difference what so ever!   .today we did a non stop 90 miles and when pulling away from a motorway roundabout i thought i had a lumpy moment on petrol but the kids were chatting and the cd on so can not be 100%.but it was making me think of prehaps a dis coil pack with cracked ceramic??.the car is manual and the engine vibe through the gearstick on lpg is so obvious and on petrol is non excistant. i can not afford to through loads of money at the car as the gas kit came f.o.c and i feel very lucky to get it but i have already spent out on plugs and leads i havent needed so will the dis oil pack be likely to be further wasted funds , could it be anything else? the mil light does not come on and the prinz lpg was extremely smooth on the other omega prior to removal. the gas tank was low so i have put a further 20 litres in just in case it was some kind of pressure issue..thanks for reading through hope you can help   andy

[feeutfo]

if its ok on petrol then the problem lies with the lpg system most likely, esp if you've changed the plugs and leads. But as you suggest, lpg will find any fault you may have with the ignition system.

If the prinz system comes with any software i'd be pluging the lap top in to check the evaporator is getting up to temp. and that the pressure is sufficient. The stag system some of us have on here needs about 1.3 bar and 20c minimum to work.
Also worth double checking its all connected up correctly, esp as it worked ok on the previous car.
However there are more experienced than me on this subject, i'm sure they'll be along soon. :-)

[andy.]

Thanks for the advise i`ll try to get a plug in tomorrow and check the pressure,it just feels so electrical just like leads,but its not!...

[Bionic]

Had the same experience with a few lpg dual fuel conversions on two different motors. Got rid of them both because despite spending loads of wonga with different specialists the problem kept re-appearing.
My current thoughts are that if the dual fuel system is fitted during the cars production then it is reliable. If it is an aftermarket fitment then they are prone to problems. My previous cars were Vauxhall Senator and a Jag XJ. Not cheap cars and not cheap conversions. Massive 'repair' bills though, time and again.
My advice would be to stick with a single fuel that you know to be reliable.
GudLuk
Ray

[albitz]

Several members on here have done very reliable/successful LPG conversions.It needs to be set up by someone who knows what they are doing imo.
I would suspect dispack tbh,as Chris said,if there is an ignition type problem the LPG will find it/magnify it.
Have you checked your plug wells for oil ? these type of problems often stem from blocked breathers which cause the cam cover gaskets to leak oil into the plug wells,which then progressivelly damages the HT components.
Might be worth swapping a dispack with someone elses to diagnose,or if that isnt possible source one from a breaker on here or elsewhere.

[Lazydocker]

Hello and welcome Andy

Firstly I'll ask if the system has been calibrated and mapped since being swapped from the other vehicle... If not you're fighting a losing battle as it will have all the settings front the last car!

My first guess would have been an HT problem but need to check fault codes as you've already done plugs and leads. Do a paper clip test, details in the guides section, and post up the results.  Once we've checked the results we can (hopefully) rule out a lot of things... Unfortunately any HT fault rarely brings up a fault code!

Next step will be to check all your work and connections from transferring the system over... Go right back to basics and check everything! Could simply be an injector pipe which is leaking for example or connected in the wrong order!

As for the comments about aftermarket LPG systems... They are only ever as good as the fitter IMHO... As long as the system is suited to the car, and fitted correctly, there is no problem whatsoever! I have done about 30k since fitting mine and, apart from 1 small problem with a sensor and general servicing and tweeking (more as an experiment than anything else!) it's been trouble free Of course, it does depend on the condition of the engine to start with and the maintenance!

[omegod]

Mine was running rough on gas and felt like a couple of cylinders werent firing, changed the lpg filter and it ran sweet as! worth a try for a fiver.

[feeutfo]

Had the same experience with a few lpg dual fuel conversions on two different motors. Got rid of them both because despite spending loads of wonga with different specialists the problem kept re-appearing.
My current thoughts are that if the dual fuel system is fitted during the cars production then it is reliable. If it is an aftermarket fitment then they are prone to problems. My previous cars were Vauxhall Senator and a Jag XJ. Not cheap cars and not cheap conversions. Massive 'repair' bills though, time and again.
My advice would be to stick with a single fuel that you know to be reliable.
GudLuk
Ray

Well, all anyone can do is draw on their own experience, and if fitted "professionally" i'm not suprised there have been problems going by some of the stories on here.

However, the vast majority of installs on here are diy, and the experienced gained by those that have fitted an lpg system has been handed down to others so people, like myself, can fit their own. Ironic really, that diy seems to be the best cheapest and most reliable way to go about it. Of all the installs on here, only diy and Entwoods installs seem to be successfull. Mine cost just over £800 and about 3 weekends of actual work time(but lots of pondering and research) to complete.

Sorry to hear you've had agro, but my experience has been very successfull, thanks to members here. :-)

[andy.]

Thanks to all for the help and suggestions, on the sugestion of running on the old cars settings, i got it hooked up to a laptop with some prinz software. the pressure was running ok however the results look like injector 3 and 5 way be wired the wrong way around,so gonna stick on petrol and have a go on saturday swapping them over and then see how it goes then.I will post up the findings as son as i know  many thanks

[Lazydocker]

Thanks to all for the help and suggestions, on the sugestion of running on the old cars settings, i got it hooked up to a laptop with some prinz software. the pressure was running ok however the results look like injector 3 and 5 way be wired the wrong way around,so gonna stick on petrol and have a go on saturday swapping them over and then see how it goes then.I will post up the findings as son as i know  many thanks

It happens to the best of us

I wasn't suggesting you should run on the old settings, I was saying it needs to be calibrated and mapped for this car But obviously not until you've confirmed the wiring is correct

[Kevin Wood]

Ahh, the old "2 injectors swapped" chestnut. Been there, done that.

Interestingly, it makes practically no odds if you swap 2 injectors on petrol, but bu**er me does it misfire on LPG! I guess it's much easier for adjacent cylinders to scavenge the LPG if it's injected at the wrong time whereas petrol just sits behind the inlet valve until it opens.

Kevin