Lpg on car fitted with mechanical fuel injection

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volvo940 · #1 Post by **volvo940** » Mon Aug 21, 2006 5:16 am

volvo 740 230E engine with continuious mechanical injection system, 1987 model. how do you cut the petrol supply to this type of setup, will the injection system be damaged by running dry when I'm on LPG. would it be better to loose the dual fuel option and go LPG full time. I'm tranfering a closed loop leonardo system to it from my last car (940 with electronic injection). Sorry if this is double posted but my posts don't seem to be getting through

lebesset · #2 Post by **lebesset** » Mon Aug 21, 2006 3:24 pm

well , I ran mine for 150K miles like this and it always ran perfectly if an evil day came and ~I had to run on petrol ! make sure the electrical feed is the one to the fuel pump which is off when the engine has stopped , and actuated for start up from the starter motor circuit!

bob · #3 Post by **bob** » Mon Aug 21, 2006 9:27 pm

I agree. The bosch CI system will not be damaged if you turn off the pump. All you do is to switch out the power supply to the fuel pump relay. Then the injectors just sit there for the ride and do nothing. If a CI equiped car is left parked up for a long time they do not damage themselves so I see no reason as to why the system would be damaged if it is turned off. The system is very reliable. I reckon that the air flap on the metering head might be best if it was held open.I believe that there is a device that will do this. The only problem with LPG only is can you always get LPG. If you do go all LPG then the holes in the inlet manifold were the petrol injectors go could be used for the LPG injectors and the metering head could be removed leaving only the throttle body in place making for a neat job. I dare say a performance shop would be able to supply a better air filter set to replace the gap left by the metering head/ air flap ass. The petrol tank could be removed and a LPG subsituted in place with the filler under the exsiting petrol flap. Depends on how much room under the car there is bearing in mind the ground clearance. This could be a very easy conversion.

classicswede · #4 Post by **classicswede** » Mon Aug 21, 2006 9:52 pm

Hi, the best bet is just to cut the fuel pumps. We fit a 70mm M/F mixer onto the intake of the air flow meter on these. The mixer is fine there as it is still very close to the inlet manifold. By doing this there is no need for a door opener.

bob · #5 Post by **bob** » Mon Aug 21, 2006 9:58 pm

If a mixer is used then it is even easier.

volvo940 · #6 Post by **volvo940** » Wed Aug 23, 2006 8:36 pm

anyone local to me A10/M25 got a 70mm m/f mixer C S where are you?, got a phone No lin at biscit.biz

lebesset · #7 Post by **lebesset** » Thu Aug 24, 2006 4:07 pm

I syfrankly I would fit one of the old 3 position manual change switches , off, lpg , petrol pump then all you have to do is find the petrol pump feed near the fusebox , run it to the switch with a feed back to the fusebox , then select what fuel you want ; also acts as an extra immobiliser if you leave the switch in off ! mine used to start fine on lpg except in cold weather when I started on petrol then switched over manually no auto switch over ? fine by me , just read the number of people here who get problems with that ! I stick to KISS

volvo940 · #8 Post by **volvo940** » Thu Aug 24, 2006 6:46 pm

"I'm tranfering a closed loop leonardo system to it from my last car " now I need the nut to weld to the exhaust

classicswede · #9 Post by **classicswede** » Thu Aug 24, 2006 9:49 pm

Peter our phone number is 01407 832 290 - we are more than willing to give advice over the phone as you asked. Mike