Fuel Starvation ?

[Raggylad]

Having a seriously weird fuel (?) problem on my '83 110 V8.

She starts & runs fine on LPG, but - when started on petrol started with difficulty, ran roughly for about 30 seconds then cut out - repeatedly. Pumping the accelerator prolonged this to about 45 seconds. That was yesterday - today she won't start at all on petrol.

Possibly relevant facts/related symptoms ?

- LPG is a simple single point induction system, injecting into the air intakes of the (Stromberg) carbs. Petrol system is standard as to pump & filter.
- Petrol in tanks is only 2 weeks old.
- New fuel filter fitted about 2 weeks ago, but had been running fine.
- Fuel pump makes the right fast then slower ticking noises on startup.
- Had been experiencing petrol vapourisation problems when running on the hot side in heavy traffic.
- Had just fitted braided fuel hose from filter - fuel solenoid (part of LPG system) - carbs, to try to alleviate vaporisation problem.
- Serious backfire when starting from (very) cold on LPG had blown front silencer box 4 weeks ago, so there is a new box (a pipe run to Y pipe) fitted. This sounds a bit rough on start up on LPG since the start of the petrol problem - with an intermittent burble/rattle from the area of the silencer box until the engine is warmed up.

What I have done so far:

- Reinstated the original fuel pipe; checked all fuel connections for petrol/air tightness.
- Checked the top half of the carbs. Cleaned pistons & needles & checked diaphragms (OK).
- Run the system in the emergency, petrol-only, override mode - no joy.
- Disconnected the LPG solenoid to see if it was the LPG ECU playing up - no joy.

Thoughts and/or advice urgently needed. Not a crisis - can still run on LPG - but we're meant to be going on holiday, towing the boat to an LPG-starved area (West Pembrokeshire) from next Monday !

Sorry for the rather long post - but if I had any hair left, I would be tearing it out !

Thanks.

[Basil]

Try taking the petrol cap off the tank and try starting it, that will check if it's air locked, then pull off the return pipe and turn the ignition on and see if the petrol is actually flowing, it sound's to me like fuel starvation mate.

Hope this help's Baz

[Skye Stage 1]

As well as what Basil says, try rigging up a gravity feed petrol system to the carbs. This should show whether it's a carb problem, or a fuel line problem.

Best of luck sorting it.

[Raggylad]

Problem solved. The petrol tap/solenoid in the LPG system had stopped working.

[Basil]

Problem solved. The petrol tap/solenoid in the LPG system had stopped working.

Glad you got it sorted mate

Cheer's Baz