I have a volvo v40 1997 (R) plate 1.8 engine and since the other week when i jump started it (i flattened the battery), the engine doesnt idle properly but instead idles about 2500 - 5000 rpm's going up and down and then below that till it cuts out.
it drives fine but when going slow when the revs would be low it cuts out (quite frustrating).

my brother conected it to a diagnostic machine and got the the follwing codes:

1) 0000F -valve relay faulty
2) 0501 - power supply open circuit

i realise one of these relates to the abs relay but wondered if anyone can help me please.

thanks very much
lindon

 

Check you wiring from the firewall to the coils, then check the Fuel Pump Regulator. this car looses it mind when it has an electrical issue.

 

What is the condition of your battery? Just driving it won't fully recharge it and if the battery is old it may not fully charge.

Hook it to a good charger to get the battery fully charged or just replace it if more than four years old. The computer needs good power.

If the battery is known to be good...do you smell gasoline? Is it hard to start? If so, then you may have a bad fuel pressure regulator.