Zafira 2002 1.8 - Strange power loss on motorway - left curves only!

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Sun 24 Oct 2010 04:52
Zafira 2002 1.8 - Strange power loss on motorway - left curves only! - BoDuke

Dear Backroomites,

Have a strange problem with my 2002 1.8 Zafira, I hope someone might be able to shed some light on it. The symptom is power loss after prolonged left-hand curves on the motorway, but only if the tank is around a quarter full or less. The car gets about half way or two thirds of the way around (depending on duration of bend) and then starts to lose power, which continues until the car hits the straight again and power picks right up. This effect never occurs on right hand curves, and filling the tank also makes it disappear. Effect is more pronounced on longer or sharper left curves.

Applying a bit of logic, I thought that the petrol tank must have two supply pipes leading out of it, one on the left and one on the right, and that the right hand exit had become blocked with crud. As the petrol swills to the right side on left curves, the left pipe loses supply and the right pipe, being blocked, can't compensate, hence temporary fuel shortage on prolonged left hand curves.

But then I took it to my local mechanic and he told me that the Zafira only has one supply outlet from the petrol tank, and if that was blocked, it wouldn't go anywhere.

So I'm stumped, and so is the mechanic.

All suggestions most gratefully received.

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Sun 24 Oct 2010 09:33
Zafira 2002 1.8 - Strange power loss on motorway - left curves only! - clewsy01

I would presume that when you go round the bed that the feed is picking up some dirt or something from the tank and then when straight the fuel cleans it through. I have not suffered power loss but on my 1.6 Zafira same year i find exactly the same, especially when i get on the A19 southbound from northumberland. My fuel will drop, sometimes if i have a bit less than quarter thank the fuel light will come on.

Is it worth trying to drop then tank and clean it? is that possible? i dont know, however i would not be too concerned. I also bet you notice that your fuel level can vary a lot when parked up on a hill, slope or kerb and not give an accurate reading. A common issue on the zafiras and astras built on them model types.

Maybe try changing the fuel filter, filling the car right up and seeing if that makes a difference. Fuel filter is on under the passenger side rear door of the car, maybe if that is paritally blocked then when the cars balance shifts to that side then if it may move the blockage and restrict the flow, hence evening when level.

HTH

michael

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Sun 24 Oct 2010 15:27
Zafira 2002 1.8 - Strange power loss on motorway - left curves only! - doofer

The fuel pick-up sits in a pot in the bottom of the tank. If the valve on the pot has failed, allowing it to empty under centrifugal force, it will cause these symptoms. Could also be the fuel return pipe inside the tank has come adrift, as it feeds in to the pot.

With the fuel level low the pump can be removed and the pot/return pipe checked, observing all safety precautions of course!

Not sure if the pot can be replaced or repaired, or if you need to replace the tank .

Might be easier to just keep the tank topped up!

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Wed 27 Oct 2010 02:40
Zafira 2002 1.8 - Strange power loss on motorway - left curves only! - BoDuke

Thanks for the help, not sure it's the fuel filter as I think it's been changed since the problem started but I'll check with the mechanic.

As for a blocked fuel return pipe, the mechanic thought the same, but he said that if it were so, the fuel consumption would shoot up. That hasn't happened, getting the same mpg as always. Is he right about that though?

I think I'll just try and remember to fill up before each motorway trip, still, can't help thinking that it might develop into something more prevalent and leave me and the family stranded some day soon. Fingers' crossed, and might be time to start saving up for a Mazda 5.

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Wed 27 Oct 2010 14:35
Zafira 2002 1.8 - Strange power loss on motorway - left curves only! - doofer

I was referring to the part of the return pipe inside the tank coming adrift and not flowing in to the pot rather than a blockage.

A blockage would cause running problems, including high MPG, as the fuel pressure would be too high.

I think, however, it will be a failed anti-drain valve in the pot., which wont get any worse, just keep the tank above quarter full.

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