Lumpy Skoda

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Sat 30 Aug 2003 10:48
Lumpy Skoda - Mike200
The engine in my grandfathers old 1993 Skoda Favorit has started acting very strangely. Here goes the story...

Filled it up monday just gone, and yesterday (friday) he started it and a very strong vibration was going all the way through the car. Also a strong smell of petrol could be smelt, but stronger towards the back of the car.

I had a look at it today. When it started it was running very erratically, and almost died, but my grandfather kept his foot on the throttle to keep it alive. I noticed lots of air in the fuel filter, but by the time the engine warmed up, it was almost gone and was running near enough, normally. I then prodded the throttle, and the engine bogged down in itself, and almost died again.It recovered, but again, there was a really stong smell of petrol, more noticable towards the rear of the car. At the rear of the car, the exhaust was acting strangly too. It was exhausting normally, just "Phutting" every now and again, and when it did, the exhaust swung quite away, as if it were releasing quite a high pressure.

I am having trouble putting this together. My mind keeps straying towards a fuel leak, fuel coming out (smell), air getting in (rough running) but why would the exhaust be acting strangely?
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Sat 30 Aug 2003 11:31
Lumpy Skoda - Aprilia
I assume that this is carb. engine without a cat?
I would suspect that the car is running rich - possibly due to a carb. fault such a the needle valve not closing off properly.
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Sat 30 Aug 2003 12:22
Lumpy Skoda - Kuang
I have a 93 Favorit (but the fuel injected second-half version) with only 36k on the clock and it too occasionally idles roughly and whiffs of petrol for a little while after starting, although not to the extent you're suffering. Mine has just been through its MOT too, and everything checked out perfectly. How's the air filter and box looking?
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Sat 30 Aug 2003 15:47
Lumpy Skoda - Dizzy {P}
Mike, is it running on all cylinders? I wondered if the rough running when cold is due to misfiring and the smell of petrol towards the rear is the resulting unburnt petrol? The smell could be particularly noticeable with a cold engine since the air/fuel mixture will be quite rich.

If the engine was 'missing' on one cylinder, or perhaps more than one, this could make it hard for the engine to pick up when the throttle pedal is pressed and I think it could cause stalling.

Misfiring could cause the engine, and hence the exhaust system, to shake quite violently. I assume that when you say that it was exhausting normally for a time, this was when the engine was running almost normally and not when it was running erratically.
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Sat 30 Aug 2003 16:41
Lumpy Skoda - Mike200
That is correct, and I think you were right, it was missing on one cylinder. A new set of plugs and a new fuel filter have been fitted and the car is running like normal again, but thanks for your response.
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