EB problem

[trick_xd]

O.K. so i have a m8 that has a EB (I6 auto)
on L.P.G. it is great it has power and runs fine
on PETROL it is so slugish.

If i put my foot down over half way it dies.
it missers just off idle and cant get more then 70km.

I have replaced the fuel pump and filter
I have replaced the fuel rail and injecters(it in my car)

1 Thing i did notice was that if i took the vacume hose off the fuel reg then it was just a bit better if i used the gears and held it in 1st till 2 1/2k then changed to 2nd it would take off a bit but then it would die out at higher revs again

On a flat rev it is great you do not feel or notice a problem at all .

So if anyone has had this problem before what did you do.
I am stuck. as by rights it should work fine.

So It has good fuel and pressure with new pump and filter as well as a new fuel rail and injecters.
It runs on L.P.G. great so it has good spark.

Where do i start looking..?

Cheers in advance

[eav8]

was the dizzy recurved to suit LPG? If so that could be part of your problem as LPG has more initial but less total advance than petrol. has o2 sensor died? has map sensor become faulty?

A lot of things aren't used with LPG that are with petrol and if engine has been retuned / setup for the LPG then it could behave erratically on petrol.

A quick one....If petrol is not the best why not just switch to straight gas and enjoy the cheaper running?

[trick_xd]

The car is used as pilot car for wide loads and some times there is no gas around for it to fill up on so it needs to be running on both gas and fuel

the problem has been coming and going over the last 2 mths some times it runns great on fuel and not a problem and then other times it just wont even start or drive on fuel. Now it wont realy drive at all on fuel

the oxy sencer is 1 thing i thought about but as it is still running great on gas i thought that it would still be o.k. as the gas system hooks into it as well.

[NZ]

Have you tested the fuel pressure? Did you try another reg?

Pressure at idle should be 200kpa
Engine off it should be 250kpa

Do a pressure drop test. It shouldnt drop more than 10% in 10 seconds after the pump stops running.

The fact that with no vac to the reg it ran better could indicate low fuel pressure.

[trick_xd]

Yep we done that and then i changed the injecters i changed the reg as well .. The car will be back here on thursday and i think the next thing might be as eav8 said I might just change the oxy sencer just to cross it off my list as well
So I have Done.

new fuel pump
new fuel filter
new fuel reg - took of my car
new injecters - took of my car

next will be the oxy sencer.
Then what else to do ?