What system for a mk1 golf gti - mechanical fuel injection

[MikeyBikey]

Hi. I also have a mk1 golf gti that i wish to convert to lpg. However it's got the early mechanical fuel injection system VW developed . Any ideas on what system would be used (open / closed single point with mixer or injection based one)
Thanks

[sijones]

Does it have a solenoid on the injector pump that you can cut out to stop the petrol? then i guess you could use normal single point....

[Gilbertd]

Mk 1 GTi has Bosch K Jetronic mechanical injection. Your only option is a single point but the difficulty is in shutting off the petrol system. You are not the first to ask, there's been a number of people asking about trying to convert older Mercs and Audis with the same system.

[Tubbs]

You just knock the fuel pump out. Thats not the problem. Finding the mixer and getting the air distro flap out the way is. First bang it bends that up and it will not run on petrol. Even after you have pushed the distro plate back down it never runs well on petrol after that.

[Gilbertd]

Not 100% on the Golf but I know that other cars that used the K Jetronic also had a fuel pressure accumator after the pump, so even after the pump stops there is still a reservoir of fuel under pressure stored in that. As you rightly say, the biggest problem is that damn great plate on a wobbly arm that sits in the intake........

[Tubbs]

Yeh thats the kiddie ! What a right royal P.I.T.A they where to gas convert.

[Gilbertd]

Weber used to do a carb conversion for the Mk1 GTi. Now that would be a way to go. Junk the mechanical injection, fit a carb (which releases more power anyway) and then fit a mixer. Simples.

[MikeyBikey]

thanks for the response. B*gger.

It's my daughters and I've been promising to convert it for her to help her save money. She lives up country and comes back to visit. I live in sunny (sometimes) , Cornwall.

[MikeyBikey]

Weber used to do a carb conversion for the Mk1 GTi. Now that would be a way to go. Junk the mechanical injection, fit a carb (which releases more power anyway) and then fit a mixer. Simples.

yeah, sounds like a gud 'un

Ive been mucking around with the weber on my scimitar to develop a throttle body. Could do the same .

Got me thinking

Thanks G

[Gilbertd]

It used a 28/36 DCNF if I remember right. It's a twin choke, non-progressive carb so both chokes open at the same time. Effectively two carbs sharing a common float chamber. The original non-injected Ferrari 306 used 4 of them, a choke per cylinder.......

http://www.webercarbs.co.uk/

[Tubbs]

You can get them to work ok. There are a few different ways, first one is to replace the plate. The one for gas has holes in it and another rubber peice over the top. So when it has a bang it blows through the holes, lifts the rubber and you carry on on your merry way. Inlet vac pulls the rubber back down to seal it.
The other is a mixer with a little plunger built into it. It uses gas to push the piston down, pushing the plate out the way. Then when you go back to petol the gas from the reducer obviously disapears ? And the flap operates as normal. I think the only reducer that has this ootion is the omvl r90e or super. Mind you be a bit overkill for an engine of that size.

[MikeyBikey]

Thanks. I'm not overly familiar with the existing injection system nor the nuances of lpg so I think I'll investigate the carb conversion first.

[MikeyBikey]

It used a 28/36 DCNF if I remember right. It's a twin choke, non-progressive carb so both chokes open at the same time. Effectively two carbs sharing a common float chamber. The original non-injected Ferrari 306 used 4 of them, a choke per cylinder.......

http://www.webercarbs.co.uk/

Wow.

The essex v6 uses the 38DGAS which works on exactly the same principle. Both chokes open simultaneously and in effect one choke supplies each bank of three cylinders. However there are bespoke inlet manifolds that allow up to three of these carbs (emulating the ferrari logic, one choke per cylinder) but they're pretty scarce ( and use a lot of fuel!!!)

Anyways found the appropriate carb. Thanks for the link. look on ebay first

http://www.fastroadcars.co.uk/shop/inde ... oductId=32

[Gilbertd]

That carb is to replace the original Pieburg fitted to the non-injection versions, so you'need an original manifold too. Look here http://www.dmcnews.com/Techsection/Bosc ... ch-12d.pdf for full details on how the injection system works. The big flappy thing in the intake is your biggest obstacle when it comes to fitting an LPG system.