Hello everybody

I have a 2nd hand Ford Fiesta 1.6, 2010 model (titanium) with 73,000 km on the clock, South Africa.

Everything was running smoothly up until a couple of months ago when we ran into some faulty engine trouble, and I was wondering if anybody could help me diagnose the problem before I budget to fix this car.

When the engine is idling on a cold start, the rev's seem to fluctuate very oddly, up and down. Coupled with this, is a very strong smell of petrol at which I assumed was because of the catalytic converter, however I am not sure. Around a month ago I noticed that if I rev the car while the engine is still cold, strange black spots seem to spew out of the exhaust, all which fixes up when the engine has warmed up. We're worried it may be the automatic choke feeding the engine too much petrol when it is warming up.

This, however, isn't my biggest concern. One day when driving around my town, I experienced a sudden big drop in power while a messaged appeared "Engine fault, service now." This is an intermittent problem, which is why I am unable to pick up on what it might be. After switching the car off for a while and back on again, the problem seems to disappear. This has happened to me about three times in the past months. The car literally runs perfectly up until the message appears, what could possibly cause an instant drop in power, that suddenly fixes after time?

The car is still 7000km's off of it's next service, which is why I am afraid to do anything drastic. Am I wrong in assuming it may be a faulty spark plug which resulted in a sudden drop in power? Or perhaps the computer box has a fault. Either way, I think this car just plainly needs a service even though it was only purchased earlier this year.

I really hope somebody can help. Thank you for your time!

Brad

If it stinks of petrol it's over fuelling, could be something as simple as a temperature sensor failing and telling the engine it is cold hence the excess fuel.

The black spots are soot building up in the exhaust, have you tried taking it for a good high speed blast on the motorway?

Has to be worth checking every breather hose. Any hose that connects to the induction or engine ventilation system, if holed through damage or decay, can affect the fuelling. Extra air getting in can cause auto enrichment, a bit like the engine being cold and needing "choke"....

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