ghosts in the machine

khlyavich

just had a white knuckle ride from delgany to sandymount,mostly on the hard shoulder.My 1994 audi 200e seems to have a weird problem- minutes after i come out of a petrol station having filled up,the dam car starts juddering and loses power,limping to the nearest lay by.this has happened numerous times so its not dirty petrol.i take one of the leads of the battery and put it back on.then use the jump leads(permanently stowed) with the help of a passer by.it then works fine until i go to another petrol station.it must be electronic ? maybe the petrol pumps give off a little charge and temporarily fritzs the electronics..or its the fuel sensor in the petrol tank ? i would of course take it to a mechanic but ive been circling the plug hole for a while now financially so would very much appreciate any help. thanks in advance.

Atlantic Dawn

Fuel filter perhaps?

khlyavich

Atlantic Dawn wrote: »

Fuel filter perhaps?

well its happened 5 or 6 times in different stations so its not dirty petrol.also when i restart it using the jump leads it works perfectly so it must be elctronic.its like rebooting the cars computer.

biko

If the fuel filters doesn't sort it it could be the fuel pump in the tank.
It's a long shot but occasionally a fuel pump will warn you that it needs to be replaced. It will overheat and stop working for 20 minutes or so. If you let the car sit for a half hour (more or less), it will start again, as the fuel pump cools off and begins working again. Have the fuel system diagnosed to be sure it is the fuel pump and not the relay or wiring causing the problem, and have the offending part replaced.

khlyavich

Magnus wrote: »

If the fuel filters doesn't sort it it could be the fuel pump in the tank.
It's a long shot but occasionally a fuel pump will warn you that it needs to be replaced. It will overheat and stop working for 20 minutes or so. If you let the car sit for a half hour (more or less), it will start again, as the fuel pump cools off and begins working again. Have the fuel system diagnosed to be sure it is the fuel pump and not the relay or wiring causing the problem, and have the offending part replaced.

the odd thing is,i have no problems with it in the intervening days, ie. when i dont need to get petrol.on those days it works like a charm.its just something happens when i put petrol in..which led me to believe it was a charge coming off the petrol pump or the fuel when it goes into the tank..possibly affecting the fuel gauge sensor..or sumthing .

biko

It could be sediment in the bottom of the tank that is stirred up by adding petrol.

khlyavich

Magnus wrote: »

It could be sediment in the bottom of the tank that is stirred up by adding petrol.

perhaps thats it, although then the fuel lines would become clogged and it wouldnt work.
never mind,many thanks for your help.will see where the next episode leaves me.

hiluxman

i would be inclined to think it could be a crankshaft sensor fault. you should check and see have you a spark when it doesnt start. i cant remember if that model has a crankshaft sensor or a hall sensor in the distrubitor. doesnt make sense why it only happens after fillin up th tank

Ive heard of petrol pumps interfereing with immobilizer signals and that the cars would start when its towed out of range of the petrol pumps but thats not happening here

khlyavich

hiluxman wrote: »

i would be inclined to think it could be a crankshaft sensor fault. you should check and see have you a spark when it doesnt start. i cant remember if that model has a crankshaft sensor or a hall sensor in the distrubitor. doesnt make sense why it only happens after fillin up th tank

Ive heard of petrol pumps interfereing with immobilizer signals and that the cars would start when its towed out of range of the petrol pumps but thats not happening here

when you say a spark,what do you mean exactly ?
typically it happens between 3 and 5 minutes after leaving the garage.it looses power,judders along,wont go over 20 miles per hour.then when stopped and turned off,it wont start even though it makes all the right starting up sounds,it just doesnt catch.i then use the jump leads to reboot and all is fine.

jimmyw

khlyavich wrote: »

when you say a spark,what do you mean exactly ?
typically it happens between 3 and 5 minutes after leaving the garage.it looses power,judders along,wont go over 20 miles per hour.then when stopped and turned off,it wont start even though it makes all the right starting up sounds,it just doesnt catch.i then use the jump leads to reboot and all is fine.

They mean a spark at the plugs. Take out one and check if you can.

loobylou

Next refill use a petrol canister away from the pumps. This way you will be able to eliminate either the petrol being the problem or the pump.

Theta

loobylou wrote: »

Next refill use a petrol canister away from the pumps. This way you will be able to eliminate either the petrol being the problem or the pump.

Hold on a second it cant be the car picking up a charge from the pump! Fuel pumps have to be earth because you know discharge from a fuel pump could cause an explosion!

langdang

I'd agree with the debug suggestions of making the next fill from a jerrycan or whatever rather than a pump. Worth a shot to see if still happens?

Theta wrote: »

Hold on a second it cant be the car picking up a charge from the pump! Fuel pumps have to be earth because you know discharge from a fuel pump could cause an explosion!

There have been numerous cars recalled for static problems when refuelling. But you're right, hardly likely to charge jumping from pump to car, but quite possible the other way?

khlyavich

very true on the charge from the petrol pump..doh ! i guess the tension must be getting to me, with these journeys taking on all the drama of the film "speed".
stopped off on the way home today and put 6 euros worth into a jerry can and then into car.will try a spin a little later.

the merchant

I think it's a tank breather blockage. When you're filling up does the pump click off like it full a lot?

khlyavich

the merchant wrote: »

I think it's a tank breather blockage. When you're filling up does the pump click off like it full a lot?

actually,no.it flows just fine.

langdang

the merchant wrote: »

I think it's a tank breather blockage. When you're filling up does the pump click off like it full a lot?

Heard of an Almera with a dodgy solenoid for venting the tank that gave weird trouble... took a while to diagnose because it was intermittent... you might be onto something...

khlyavich

langdang wrote: »

Heard of an Almera with a dodgy solenoid for venting the tank that gave weird trouble... took a while to diagnose because it was intermittent... you might be onto something...

but if thats the case,would it follow that after rebooting the computer(jump leads etc)the car runs perfectly ?

khlyavich

just been out for a spin.all seems ok now.seems it might have been the petrol pump-either the power of the flow from the pump is bringing up sediment sitting on the bottom of the tank or its static affecting the computer.

mickdw

I dont understand why you need jump leads. Are you not just taking a lead off the battery to reset everything?

khlyavich

mickdw wrote: »

I dont understand why you need jump leads. Are you not just taking a lead off the battery to reset everything?

it wont start without a jump,certainly not after its been juddering.i have to take the lead off the battery,replace it then jump start it and it goes.i think it reboots the computer..could be wrong.