Engine help please

My daughter has a 1998 Peugeot 806 SV with a 2.0 litre petrol engine, normally aspirated.

Recently, a problem has manifested itself. Instead of turning over immediately, it takes a while to start and then won't tick over but dies, unless I keep my foot on the accelerator.

When I slow at junctions, the engine stalls and I have to restart it.

There is also a strong smell of unburnt petrol from the exhaust and mpg is shot to hell.

A while ago we added some Redex to the tank and it seemed to have done the trick but now it's back to it's old games.

Any ideas?

Where's Handyman when you need him..?

Carburettor or injection..?

Carb.

Not really enough info to be precise. But first be aware of a possible fire hazard.

Are you sure that the petrol smell is only coming from the exhaust? It may be coming from under the bonnet. In this case the most common cause a too high fuel level in the float chamber so that the carb floods. This usually comes about due to the float needle valve leaking so that it does not control the fuel level as it should. The most common reasons are a very worn needle valve or often a tiny bit of dirt on the needle or seating.

Less common are things like the float setting out of adjustment, or (not often) even a punctured float. There are other things like an overpressuring fuel pump etc, but I don't want to confuse you and reccommend that you check the float needle valve first and if in doubt just replace it, although you may have to readjust the float/fuel level after fitting a new one. Please remember that in extreme cases fuel can spill over the hot parts of the engine when the engine is not running or even when running slowly.

When it runs properly there is no petrol smell, and the smell definitely seems to be associated with the exhaust, not the engine compartment.

You say that it won't idle. Is it misfiring before it cuts out? Checking plugs and leads for condition and leakage might be helpful although I wouldn't rule out carb trouble even if there is no smell under the bonnet. I can usually identify whether it is an electrical or fuel problem by the way that it misfires or cuts out, but I can't do that in this case obviously.

Usually an electrical fault causes an abrupt or erratic stall, whereas fuel problems seem to cause a soft petering out stall, with the engine trying to run backwards on occasion.

Sorry if that sounds odd but when you just have a "feel" for these things born of years of experience it is hard to put it into words. by the way,I only have one post left for today.

No misfiring, just stops. Are you a mobile mechanic, because you are welcome to do a job on it; I live in Compton, between Winchester and Chandler's Ford. If you can, I'll email or PM you my contact details.

Sorry, I can only advise, and i'm limited by your (understandable) inability to describe the symptoms exactly. If you don't mind paying i'm sure there must be a reliable garage/mechanic in your area. From your description it could even be intermittent fuel starvation, so you see from my end it sounds a bit ambigous. I was just trying to save you paying out unnecessarily on what might have been something very simple. Funny thing is, I had the same thing happen with one of my vehicles and it turned out to be a tank of bad petrol. It may have had some water in it, although I didn't bother to really check that out. Suffice it to say that it was the only time that I filled up at other than my usual supplier! Best of luck with the problem, I hope it gets sorted for you soon.

Automatic choke sticking closed, and subsequent over-fuelling, would give those symptoms, except possibly the awkward starting - unless it is constantly flooded.

Any rattling from underneath? I had similar symptoms from a car once and it was because the catalytic converter had sheared in half and was blocking exhaust gasses from getting out to the tail pipe.