Poor Running on Petrol fine on LPG

[pouch]

Van has just been in for the MOT. Passed, no problems.

She is running OK on lpg, but wont idle well even when warm.
If I switch to Petrol she only barely runs, feeling like she is only running on 1 bank.

Petrol supply is fine, I was thinking this could be a blocked jet?
Would that also explain poor idle on LPG?

Any suggestions welcome, was going to have a look at the weekend.
Not done much with carbs before, so any tips appreciated.

[hammy44]

first how old is the petrol if you run on gas most of the time the petrol could be dead

[kevtherev]

Air leak
especially if LPG is poor idling too

[pouch]

Fresh Petrol,

All the vac hoses are fine, I'll double check, but think I have illiminated any air hose problems.
I have just replaced the fuel hose due to a leak in the hose wall, I replaced all the fuel hose as it appeared to be perished, even though it was replaced a sfew year ago when the recon engine went in. I assumed that it must have been rubbish fuel hose.

I was wandering if there may be some bits in the carb from the degrading fuel hose?

[Mocki]

fuel hose has a much shorter life span if its not being used, ie when running on lpg.
I would say to change it every 2 years max.

however, if yours is breaking up, or was, you maywell need to clean your carb out.

it maybe worth checking if the brake servo vac hose is perished, and the manifold gaskets are airtight

[pouch]

Cheers Steve,

spent some time on the engine checking through.
The car idles fine now, there was a poor connection on one of the choke connections.

The problem is clearer now. The engine starts and idles fine on Petrol, but when you open the throttle the engine struggles, even when warm.
If I use full throttle the reves do slowly rise, but it is not smooth and feels like its missing almost, possible fuel starvation.

On LPG the car runs seemlessly, at least it seems to.

How many jets are there on the CU carbs Solex 34's.
Is there an idle, slow and fast running jet? IN which case, it seems like the slow running jet could be blocked.