This may be long and winded but I dont know much about cars!!?

Hi lil-k, sounds like you are getting poor fuel economy. you are wise to not drive it until you have it checked. The tappets you refer to are probably the camshaft lifters, some are hydraulic which adjust automatically, others are solid and manually adjusted.Not sure on asta 1.4, some engines have no lifters and the valves contact the camshaft directly.That strong fuel smell at start up maynot be normal,common faults include engine in poor tune-sparkplugs,ignition wires,distributor cap & rotor, leaky fuel injector,leaky fuel press. regulator,even binding brakes can cause poor economy.You did not mention any starting or performance problems ie..hard start cold, poor acceleration,engine idles rough etc...this info could provide insight to your problem....check your engine oil for the smell of gasoline, and get it to a garage for detailed analysis...good luck

The problem is a restriction in the air flow. This would cause the engine to run rich and give pour fuel economy. All fuel injected vehicles have a computerized choke that is generally referred to as Idle Air control valve/IAC. This valve regulates the idle air flow though a machined passage in the throttle-body/TB. When this passage gets coated with carbon it will restrict that air flow. Most people don't realize that the term fuel for an engine actually means air/fuel mixture. With out air the engine won't run. This part can be removed, cleaned with a TB cleaner that is O2 sensor safe, and reinstalled.

This will improve start up, idle, acceleration, and economy. It can be verified by removing the air inlet tube going to the TB, open the throttle plate and checked for a black coating of carbon inside the inlet port. This should also be sprayed out to improve throttle response. A can of cleaner costs about 10 bucks and the job takes about an hour to do.

Hope this helps fix the problem with your car. Take care and good luck.

Don't like to state the obvious, but you may have a fuel leak. Check for this before anything else.I have had a couple of old cars which could not be filled more than half full as they leaked. Check outside of petrol tank for signs of leaking.Park car on dry area and check for any signs of dripping.Many tanks are made in 2 halves and have a joining flange round the middle. This is a common place for leaks, as mud accumulates on flange and causes rusting.

If you are burning excess fuel your spark plugs will show it. Remove them when the engine is cold if you have aluminum heads. If they are black with soot, then you are running too rich of a mixture, and need repairs.

As for the noise from the "tapits", get some valve lifter cleaner. I imagine they are hydraulic lifters.

Computers in cars now-a-days will adjust automatically when the oxygen sensor senses too rich of a mixture, and the car will still run smooth. However, that doesn't solve the problem of your bad gas mileage.

from your details you're getting about 12.5 mpg, i would expect something more like 30 to 40 mpg, if the engines burning this much fuel the plugs must be black, whip one out and have a look, you shouldn't normally smell petrol from the exhaust, unless the choke device is faulty and staying on all the time.

i think the tappets are hydraulic, and if they're clattering it means they lack oil or are u/s, if they were holding the valves open you would lack power and wouldn't hear any noise, and may cause high fuel consumption.

This may sound weird but do you have a locking filler cap?

Someone could be syphoning out the fuel overnight - the smell of petrol from where they spilt some!

It is most likely old and worn out. Vauxhall only built it to last for about 10 years so it has been on borrowed time for 5 years now. They pay people to scrap cars 5 years younger than yours. You have clearly made a mistake buying a bodged up heap of junk - the sooner you get rid and change it for a newer car the better it will be for your wallet

The problem is a restriction in the air flow

sure they do low octane fuel wil make tapits knock

not saying thats your car problem or not but cheap low octane wil do it

might just be a wore out car as well

your fuel pump may have a leak or you could have a hairline split from your petrol tank.