Vauxhall Omega - owned by Mr I and first converted by Go LPG

Source: Taken from: Martin Imber Vaxuhall Omega LPG conversion gone bad

LPG Conversions

Back in 2005 when I bought a V6 Vauxhall Omega I decided to save on the running costs by getting it LPG converted. I started by contacting two local companies. One at Redditch and one near Worcester.

I was not happy with this conversion! [External link to Go LPG site showing the conversion]

People keep finding it and asking me about it, then I have to repeat the issues and recommend DIY.

Only the Worcester one replied to my emails, and their web site was informative and it looked like a reputable company.

So I arranged a conversion the Autumn of 2005, using a Romano System N sequential gas injection (SGI) system.

Unfortunately the conversion took longer than expected, originally it was supposed to take a week but took seven days, this I was not too bothered by except for being transportless for the weekend.

The car ran fine on the test drive, but the coolant system did looked hacked around, it had taken three or so goes at getting a decent hot water feed for the evaporator, it ended up being fed from the behind engine pipes to the heater (which is the correct place on an Omega for hot water).

On the way home the car broke down on gas after using a large amount of throttle, but started OK a little later, this is due to the car cutting to petrol and the vapour pressure is too high for the injectors to manage.

Anyway it was OK for a while in the morning, but on the way to work it started running rough and switching back to petrol, I put up with this for a couple of days then took it back, the RPM feed for the LPG ECU, was suspected so was changed to a coil feed, it ran OK at the installers until on the way home it broke down.

During this changeover I was told that any more visits back to the installer would involve me being charged despite the system only being fitted for a few days. Even though the car would over pressure the system and drop to petrol I did not take it back as I was not welcome.

Anyway I investigated myself and found that the LPG system loom was routed nest the the exhaust gas recirculation valve and when the engine was fully warm it melted the loom, shorting the RPM feed cable to earth. In the short trip home this had caused the engine to stop firing on two cylinders. I started by getting the cars ECU tested, luckily it was OK, I then bought a coil pack but was unable to fit it, so had to go to the main dealer.

Other issues found were, the LPG ECU had been fitted in the air box, this suffocated the engine and at full throttle robbed it of approximately 15 to 20bhp. The coolant circuit had various pipes cut and patched where hot water feeds were experimented with. I did (wrongly) make the assumption that the installer would know what he was doing.

In the mean time I moved the loom and wrapped it with tape and fitted a fuse to the RPM feed cable at the cars ECU end.

After nearly a fortnight my car was back, it ran OK provided I didn't use full throttle on gas, I managed nearly two months of this before I had an accident on the way to work when I hit a Diesel spill and rolled the car.

I managed to get removal instructions from the installer, but the body shop would not remove the kit so it ended up back at the installers and they removed the kit under protest and changing me as far I remember £150. I collected the equipment in the loan car and took it home, along with the tow bar. I had also by then viewed my current car and placed a deposit.

Since I had retained the equipment and bought a replacement car with a similar engine, the LPG kit was going to be reused. I decided I could not afford a professional refit and I was not happy with the original fitment, I did ask the installer, if I refitted the large parts could he help me finish it off and certify it. Basically he refused to help at all and also didn't want even to do a reinstall. I managed to repair the loom and work out what was what, I would email the installer asking what something was, and he would reply at length refusing to tell me.

It took me about a month to fully identify the parts and to work out all the connections. I decided then to do a full DIY install due to the hassles of dealing with installers.

By early summer 2006 my new cars DIY conversion was ready - after repairing the kit and working out what the parts did it took me four Saturdays to convert the car. I had switched it to use RPM feed again and had mounted the components in better locations. I had a few heated emails with the original installer I requested the removal of the page about my car, the emails ended up with my final saying remove the page and do not contact me again, I received a rude reply and the page is still there.

So if you want a car which switches to petrol at high RPM, has the ECU fitted into the airbox just under the air filter, lots of water pipes cut and then threatens to charge when you want it fixed, here it is The page I asked to be removed I WILL REMOVE THIS PAGE WHEN THE LINKED PAGE HAS BEEN REMOVED

The over pressuring problem caused by petrol switching was minimised by cutting the injector duration during full throttle operation, unfortunately it leaves the car slightly weak at open loop operation, Autogas Worldwide advised me on this change.

I am not the only person to have had an issue with this installer - this chap did as well Here

Please note I will remove the mentions of the installer if Steven Sparrow from Go LPG removes the page featuring my last car complete with ECU in the air box and melting loom frying a £90 DIS pack!

My final points are as follows. Do not take notice of installs on the web site, always contact the customer first, seriously consider DIY.

Vauxhall Omega V6 caveats, the hot water MUST be fed from the main coolant pipes behind the engine, the best one is the pipe between the block and the heater bypass valve. The only place for large ECU on the V6 is in the scuttle area so keep the drains clear. The best gas pipe run is following the petrol hoses. The evaporator is best mounted under the air box or under the front wing behind the wheel arch cover.

I hope this is interesting and if you want the links removed you KNOW what to do!

These pictures are of my current installation

Under bonnet view LPG Vauxhall Omega 2.6 V6

This is an under bonnet view, I was accused of passing this off as my own, well this is the one I DIY fitted so it is my own work except for the pipework from the round gas manifold to the injectors, it was not worth redoing them and there is only one place to mount them if you are using through plenum straws. On the original install the evaporator was next to the power steering reservoir - just under the yellow cap, on this car it is under the airbox out of view