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[sassanach]

ditto!!!!

[Kevin Wood]

I'm not too sure if you are after the injector assy or injector nozzles into the inlet bridge.  I've dug them all up for you anyway.

Thanks very much. They're excellent. I was thinking in terms of a similar bracket off the plenum bolts for the injectors too.

I like the nozzle placement! Didn't quite have the guts to get them that close to the injectors with James' car. Maybe I'll be a bit more adventurous with mine?

Cheers,

Kevin

[Kevin Wood]

Are those nozzles M6 ones, by the way? There just didn't seem to be enough space to do that... wonder if you've got smaller ones?

Kevin

[Jay w]

just back from London, done 640 miles this week and 95% of that was on gas.

total cost was £68, averaged 22 mpg and that was made up of 500 miles of M way and fast A roads and the rest was stop start shunting round town.

Pleased with that, had i spent £68 on petrol and averaged 30 mpg i would have only got about 420 miles so 240 miles for free cannot be knocked.

Still want to do some more with the fueling i wonder if it running a bit rich in places, i may have a look on the PC this weekend and have a proper go at it once i have done a couple of thousand miles and let it all settle down

Total petrol usage for this week about 2 gallons  

[Kevin Wood]

Can't be bad

On the whole, when cruising, the mixture will be controlled by the Lambda sensors so, as long as the LPG fuelling is close enough for it to be pulled-in by the petrol ECU it will be running spot-on (if it's not close enough you'll get a EML). Of course, when accelerating flat out and when constantly changing speed and load the lambda sensors do not get a chance to come into operation so that's where you'll gain with fine-tuning.

The other thing that you can do is to tune individual injectors. If you get it tuned so the LPG and Petrol injector times are the same, then flick individual cylinders back to petrol you can idenitfy any that cause a change in injector duration and tweak them individually. Shouldn't be necessary but might be worth a play.

Kevin

[The Cambelt Kid]

Are those nozzles M6 ones, by the way? There just didn't seem to be enough space to do that... wonder if you've got smaller ones?

Kevin

M6? didn't know thay had a value (apart from thread)  TBH my dad did the drilling n tapping as he's a dab hand at that sort of stuff.  I could have done it, but i'm sure not as good a job as my dad did.  He's Royces engineer and has work like that down to a fine art!  A few years back he made his own turntable arm out of off cuts from the williams F1 car factory, and looking at the final product i would never of thought it was hand made, twas so good!  I think he sold it for quite a large price too!

I seem to recall that the position of my injector nozzles were at a point where there wasn't too much material to work with, hence we took it very easy.  I wanted to get it as close as possible and at a good angle, so the final location in the pics was after a good hard think, i certainly didn't jump at it too quickly.  Also one of the nozzles sheared as it was nipped up so he had to knock another up on the lathe A-SAP, otherwise i'd be without a car for work the next day.

I think if i was to do a third LPG kit, i would make sure i had another car to drive about in while the work is carried out.  Half of the problems were made worse by sunday evening deadlines.    So get another car for a few days if you can!

[The Cambelt Kid]

Can't be bad

On the whole, when cruising, the mixture will be controlled by the Lambda sensors so, as long as the LPG fuelling is close enough for it to be pulled-in by the petrol ECU it will be running spot-on (if it's not close enough you'll get a EML). Of course, when accelerating flat out and when constantly changing speed and load the lambda sensors do not get a chance to come into operation so that's where you'll gain with fine-tuning.

The other thing that you can do is to tune individual injectors. If you get it tuned so the LPG and Petrol injector times are the same, then flick individual cylinders back to petrol you can idenitfy any that cause a change in injector duration and tweak them individually. Shouldn't be necessary but might be worth a play.

Kevin

Kev,

I don't think you could be more correct!  My EML lights up when i take it easy and maintain a speed for a while, but soon goes out if i hammer her all the way home.  My GM code reader reads Fuel trim malfunction on both banks.

I did have this problem a while back so i drilled out the injector nozzles to 3.0mm and the error never came back.  But since then it's got much colder outside and the error has returned to haunt me.  It only seems to occur on days with a temp of less that 5deg's.  So i am wondering if the GM ECU is trying to richen the fuel up, which the gas nozzles are restricting again??

this error has bugged me for quite a while, so i'd be interested in any input.

Cheers
Marc

[Kevin Wood]

Hi Marc,

Sounds like your dad is a clever chap.

I was referring to the thread size of the nozzles- ie 6mm. This is what James' kit had.

Regarding having another car to run about it - I have one, but the current weather makes it a bit less than ideal :-/

I must get hold of the LPG kit and make a start on mine.

I would have thought the EML issue is down to the mapping of the LPG system. You've got it close to the limits of how far the petrol ECU will adjust and occasionally the conditions are taking it outside those limits. Depends how your system is mapped but a few hours driving round with a laptop on the passenger seat (ideally with an operator too!) should see it done. 3mm injector nozzles should be ample. We used 2.5mm on James' car.

Cheers,

Kevin

[JamesV6CDX]

So you are taking the plunge Kevin? Fantastic news. When do we come over  

[The Cambelt Kid]

Hi Marc,

Sounds like your dad is a clever chap.

I was referring to the thread size of the nozzles- ie 6mm. This is what James' kit had.

Regarding having another car to run about it - I have one, but the current weather makes it a bit less than ideal :-/

I must get hold of the LPG kit and make a start on mine.

I would have thought the EML issue is down to the mapping of the LPG system. You've got it close to the limits of how far the petrol ECU will adjust and occasionally the conditions are taking it outside those limits. Depends how your system is mapped but a few hours driving round with a laptop on the passenger seat (ideally with an operator too!) should see it done. 3mm injector nozzles should be ample. We used 2.5mm on James' car.

Cheers,

Kevin

Kev,

I might give that a go, but as the EML light takes 10 miles or so to switch on or off it could take a while to 'tweak'.  From what i understand LPG has a 15% lower calorific value if compared to petrol and i have a setting for this, maybe i should give that a tweak.

My LPG kit supplier has also just bought a 99 Elite 2.5, which will be his first omega conversion, so maybe he could shed a little light as he's using the same kit as me.

He will supply the same kit as mine if anyone is interested?  I got the cable and software too, so am able to tweak, which isn't always avaiable for free from what i undertsand.

I will dump the software on the web for all to see/compare, once i have confirmed it's ok to re-distribute.

Cheers
Marc

[Kevin Wood]

As I say, it depends on your system. James' system draws a graph of how the injectors are observed to repspond on petrol and also on LPG so it's just a matter of adjusting it until they are the same, switching between the fuels as necessary.

Another technique is to switch between LPG and petrol and watch the injector durations from the main ECU. They should be the same. If they change, it's an indication that the main ECU is having to adjust the fuelling between the two fuels, hence the LPG needs adjustment. Repeat this for a few different speeds / loads and you should have it sorted pretty quick. If the injector suration increases when switching to LPG the LPG system is too lean and vice versa.

As a final step, always try a full throttle run across the rev range and check that the lambda sensor outputs are high throughout (0.8 v is typical). This is to ensure it's not going lean under heavy load which is not a good thing.

Cheers,

Kevin

[Jay w]

i used the map that James posted up on the other thread, it was a good start point but again it did underline one thing, how different our conversions are even thought we are using the same kit....

James's starting point was a lot further down the multiplyer range, he started at .95 for mine for run properly i had to start at 1.3 and work from there....

By the time i finished last night i had less than 5% deflection and both of the curves were very close, ran it for about 20 miles and it was very good indeed, you would struggle to notice the difference.

Coming up to London today, everything running good, got to about 120 miles and the EML light came on   switched back to petrol and it went off after a few miles.....then came back on, so floored it and it quickly went off..... only came on when i was running cruise control and sat at about 80mph, so it looks like it is leaning off too much and may need a little more tweaking at mid range, that will have to be the weekend now as i dont have my lappy with me.

Overall we have done about 1000 miles now and it is getting a lot better, i am getting about 250miles to about 60 litres which i am more than happy with.

[hotel21]

Have you LPG -ers to be seen this on e-bay?  Worth it perhaps for the injector assy alone to drill out, plus the other bits and bobs....