What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
VW Polo MK4 1.9D - Air bubbles in fuel line - jasonmav

I am looking to getting this car running again. The problems it is having are:

1. Hard to start

2. Once started, very rough idle, however about 1.5k - 2k revs it runs smooth

I have noticed air bubbles flowing in the clear fuel line between the fuel filter and the fuel pump. I dont think that is supposed to happen so replaced the filter and tightened all hoses but the bubbles are still there.

My next idea is to check fuel sender in the tank and then fuel lines. Maybe check the timing if I can find out how. But looking for any ideas from those that may have experienced these sort of problems.

Any comments welcome!

Thanks

VW Polo MK4 1.9D - Air bubbles in fuel line - Peter.N.

Firstly, have you changed the fuel filter, if its clogged it will cause the pump to suck very hard and air will get in. If that's OK you have a leak somewhere, could be on the filter or the hand primer if it has one. If you can park the car on a steep downward slope and get the fuel tank higher than ther engine, it should leak fuel where the air is getting in.