Need help urgently!

[JSJW]

Hi guys I have this problem and I cant seem to solve it. My car is the V5 03 model and at the moment the engine is erratically vibrating and shaking. I have replaced the coils (all of them) and the spark plugs are quite new.
But what I cant understand is that when ever the ECU is reset the car runs fine again as if nothing has ever happened.
Then about 3 days later the problem comes again and stays there until the ECU is reset again. Now I know the problem
is about to happen because when ever I start the car it cranks and then engine turns over and starts but its very weak, the rev
will go up down up down as if its going to stall and then stations at about 1000rpm. I know if I cant solve this problem, I
may have to go to a VW dealer with no choice. Couple of days ago Ive changed the air filter also but the problem is still a
mystery. Does anyone know what the problem might be? could it be the spark leads? Because the car is erratic at stop
one or two cylinder is definitely miss firing. I want to sell my car ASAP but until I fix it i cant sell.
Anyone with ideas?
cheers

[Jmac]

Hi guys I have this problem and I cant seem to solve it. My car is the V5 03 model and at the moment the engine is erratically vibrating and shaking. I have replaced the coils (all of them) and the spark plugs are quite new.
But what I cant understand is that when ever the ECU is reset the car runs fine again as if nothing has ever happened.
Then about 3 days later the problem comes again and stays there until the ECU is reset again. Now I know the problem
is about to happen because when ever I start the car it cranks and then engine turns over and starts but its very weak, the rev
will go up down up down as if its going to stall and then stations at about 1000rpm. I know if I cant solve this problem, I
may have to go to a VW dealer with no choice. Couple of days ago Ive changed the air filter also but the problem is still a
mystery. Does anyone know what the problem might be? could it be the spark leads? Because the car is erratic at stop
one or two cylinder is definitely miss firing. I want to sell my car ASAP but until I fix it i cant sell.
Anyone with ideas?
cheers

To explain why it runs fine is because you are indeed resetting the ECU like you say, then it learns the values and sees what it obviously doesn't like and runs bad, its always going to do that till you find the fault, Have it checked mate, sometimes if its seen in the flesh itll make sense to someone who knows them. If not there is various checks that can be done.
Good luck
Jmac

[greg32]

I would say ignition and fuel is OK if resetting the computer makes it run. I would suspect the EGO sensors as they feed info to the computer to set mixture of fuel. Can you connect up a computer to monitor them? another option is to use a meter to see if the output changes from 1.0V or if the wires to them are broken.

[JSJW]

I was just researching last night and I came across something interesting that might help solve the problem. It's the Oxygen sensors. What you guys think? Engine light coming on, rough idle, engine pinging etc...how many oxygen sensors are in boras? anyone know good places to get them?
cheers