Vaporizer questions (BRC)

[James23]

Hi all,

Please see my thread about misfiring under 2k rpm and long cranking before starting here:
http://lpgforum.co.uk/viewtopic.php?f=28&t=9666

BRC sequent multipoint kit

I have just driven my car down the road and back (It did switch over to LPG)
When I pulled up and switched the car off I pulled the vacuum pipe off my inlet manifold and sniffed it - strong smell of gas. I stood back and could see gas vapour coming out of the pipe and if I held my thumb lightly over the end it would build up pressure and come out with a little "tsss" when it had built up enough pressure.

Does this mean the seal on my vapouriser is broken?
Is it worth replacing the seal or should I just swap out the vapouriser?
I believe it is this one: http://www.brcgb.co.uk/drivers-store/in ... us-reducer
which is very expensive - would I be able to install a different vapouriser?

Also-

I have an air leak on my car which causes it (sometimes) to tick over at like 2100rpm and if i blip the throttle to 5000-6000 rpm the revs will stay there and not come back down - could this be because of the vapouriser?

Cheers

[rossko]

I pulled the vacuum pipe off my inlet manifold and sniffed it - strong smell of gas.

Sounds like the diaphragm is split. Worth trying to repair if you can source a kit (but sometimes the little screws shear off and you are compelled to renew)

Anything is possible but using someone elses vap (it would need to be a 1.2 bar output if your is truly the 1200) would present a challenge accomodating BRC's unique temperature sensor.

I have an air leak on my car which causes it (sometimes) to tick over at like 2100rpm and if i blip the throttle to 5000-6000 rpm the revs will stay there and not come back down - could this be because of the vapouriser?

Doubt it - more likely sticking throttle or cable.

[James23]

Thank you for your reply.

Any ideas as to where I could buy a repair kit from?

So it is possible to use a different brand reducer (If I was to buy one brand new)? I think I may have found a used BRC one but I am not sure if it is the same one - would it matter (as long as the output is the same I take it)


I've replaced the throttle cable, suppose it could be a worn out throttle body then. Damn - was hoping it would be because of the diaphragm so i could kill 2 birds with one stone by replacing it.

[rossko]

There are three or four Genius variants that all look similar, but are not directly interchangeable, so be wary if looking at replacements and identify what you have carefully.

[James23]

OK I take it they will have different model numbers then?
Sounds like it would be best to try and repair mine though, I've had a google and cant find a overhaul kit anywhere - including the BRC site. Will try sending them an email.

[lpg-cars]

The vapourisers have different base pressure settings for different engine sizes. They have different sensors for the different systems, Sequent Fast/24/56 etc. The sensors are not always interchangeable so you need to supply full details when ordering it.
You could possibly get away with another make but you would have to make sure the sensors supply the right values. You will almost definitely have to remake brackets and pipe work.

Best option would be to consult your local BRC dealer and get a price for the right one for your car. He should be able to a better price than the website if you're nice to him.

[James23]

I have just bought a second hand unit (BRC Genius) which I hoped would tide me over until I could afford to sort it out properly with a new one.
My replacement second hand unit is a 1200mbar... my old one is a 1500 mbar, does this mean I can not swap them over? also the sensor plug is different but still has 3 pins.

Doh!

I Have sourced a replacement diaphragm so will have a go at swapping that over when I get round to buying it.

Cheers so far

[rossko]

I believe the sensors are fitted with different plugs to prevent inappropriate connection i.e. they are not compatible. You may or may not be able to physically swap the sensor that matches your system onto your "new" vap, but ...

No, your system won't work properly with a 1200 in place of a 1500. Did warn you.

[James23]

Yup, you did it was fairly cheap though so no big loss.
Will order replacement diaphragm kit this week.

[James23]

Small update:
I took the "new" vapouriser apart as a practice before i tackled mine. several of the screws snapped off in the process. I found that the "new" diaphragm was not split and it was relatively clean in there.

Worried of snapping screws on my unit that I use i squirted WD40 on them several times over the period of a few weeks.
Today i took my unit apart - no screws snapped (yay!) and the diaphragm did not have a split in it. it was a bit flimsy for 1cm at the round metal ring in the middle but i shone a torch through it and no light went through so it is not split. It was quite dirty inside the vapouriser so i cleaned it up with some carb cleaner before reassembling.

Installed the vapouriser back in my car and it is still misfiring a lot.

Any ideas? Surely now then this means that is must be an injector(s) that is at fault? But why was gas coming off the vap vacuum hose when the car is switched off?

Cheers

[rossko]

Surely now then this means that is must be an injector(s) that is at fault? But why was gas coming off the vap vacuum hose when the car is switched off?

No possible injector fault can make gas come out of the vacuum hose from the vap. It can make gas come out of the manifold i.e. the other end of the vacuum pipe. Do you still have gas coming out? From which end?

[James23]

Yes gas is still coming out. From the end that connects to the inlet manifold - this is a Y piece - one goes to the vap and the other goes to the pressure sensor thing.

[rossko]

So gas is coming out of the nipple on the inlet manifold, but not out of the nipple of the vaporiser? Goosed injector dumping gas into the manifold.

[James23]

Bit of a follow up to this as I hate it when threads don't have a conclusion!

I had the injectors ultrasonically cleaned and tested and they were all ok. all had the same resistance too which is good.
Eventually got round to replacing the diaphragm.

The car now starts on the button and no gas is leaking through the vac pipe. Not sure why though because there is *definitely* not a split anywhere in the old one! but anyway it's fine now.

Car still has a misfire under 2k. I have no more ideas so will be taking it to a specialist.