Flat spot and back firing

[A THREE]

Hi all,i have an audi A3 2002 non turbo.i pick up a flat spot in my gears 2,3 and for.It lasts for a few seconds then the power is back.Also when slowing down/gearing down i have a back fire from the exhaust.
does anyone have the same prob and could someone tell me what could be the cause.

thanx guys

 

[Paradox1]

Welcome!

could be a number of things mate. have you tried getting it scanned first. that would be your best bet to find out what the problem is.

 

[A THREE]

Hi bud ,yes i have.The scan picked up a open circut on my lambda sensor which i have replaced.Could it be a fuel pump prob or do fuel pump not give intermittent probs?

 

[Paradox1]

I think fuel pumps could cause this and eventually the car will cut out when driving.

I would check the fueling in the engine bay also. perhaps coils? but i dont know if there is a error code for that?

 

[A THREE]

Yeah i put a golf mk IV coil in(exactly the same) and still pick up that prob.Is there a way for me test my fuel pump?

 

[Paradox1]

OK I get you. Its not really a test just more of an idication but when I open the door after unlocking the car, I can hear the fuel pump priming. apprently, the longer the prime the more likely it is to be a week pump.

I cant imagine your pump would be that week though as it doesnt have a turbo sucking up all your fuel. Whats your mileage?

 

[A THREE]

going for 300k

 

[superkarl]

Thats impressive!

So after fitting a new lambda sensor that fault has gone? Because your car needs the lambda for fueling.
Deffo no more codes?

When was timing belt done? Is the timing right?
Check your spark plugs and plug gaps too.

 

[James TQ]

300K! credit to your whip! it seems alot of people recently are having the same sort of problems, could also be spark plugs, change the fuel filter. when my back seats are down i can hear a whering kind of noise that may be the fuel pump im not sure