3.5 misfiring on petrol but fine on lpg

Hi all, I'm having running issues with my 3.5, I just got my landy on friday there, it's got a Bedini LPG kit, which the previous owner has told me to start it on as it started fine on it for him. I had tried to get it running on petrol unsuccessfully until tonight, I found a switch to turn the fuel pump on, finally got it going on petrol but it's misfiring and won't rev harder than 2500rpm, yet it runs fine on the gas?

Any help would be greatly appreciated, thanks in advance

igntion timing might be set for lpg, try retarding the distributor to see of it runs better then on petrol.

this is assuming the efi system is in working order, which isnt always the case, but the lack of revs and misfire leads me to think about igntion timing.

cheers

ps. good practce remember to mark dizzy position before adjusting, and/or check timing before hand with strobe light.

would be interesting to see what it is set at.

I'm thinking the problem is possibly a faulty solenoid on the lpg system, as when I switched over to petrol it would still run on gas before I found the seperate switch for the fuel pump, so I'm thinking the gas should have been cut off (it used to not run on the petrol setting) but it's not, putting gas and petrol into the carb and causing severe over fuelling and causing it to run rich? My mate has got some spare solenoids so gonna try those hopefully tomorrow night. Thanks for your reply mate, much appreciated.

That would make sense. Over richness would give those symptoms I suppose.

Have a look at the plugs?

Maf sensor, don't some lpg kits not use the cars maf but it would be used on petrol. Try unplugging the maf and see how it drives on petrol like that

Should have mentioned before its on su's, not injection. Will try the new solenoids on Friday and see how she goes.

Ohhhhhhh, right well that's more simple then.

As long as the carbs are bleedin set up right!!!!

That was in my mind too mate, I'll do a bit of research on how to set them uo, unless you can shed any light?

I know feck all about carbs, sorry!

No worries mate lol, cheers

kenzie said:

Should have mentioned before its on su's, not injection. Will try the new solenoids on Friday and see how she goes.

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Hope sue doesn't mind!!! aye, aye!!???

My knowledge of the su's is check the dashpot oil, linkages and then find a really old man who works from a shed that smokes a pipe to set them up

I topped up the dash pot oil last night mate. I'll now also be on the hunt for the smell of a pipe and the stench of an old man haha!

Oh yeah, pipe smokers know the fettle!

Well, I've sourced an old pipe smoker to do the carbs, however it's away getting the lpg system set up just now, well it's meant to be, but it seems they don't be in any hurry to look at it, so they've got till tomorrow then I'm going to get it if he's not touched it. Grrrr!