air in diesel

[Barbecue Berlingo]

It might not be of interest to anyone this late in the day, but unexplained air in the fuel line means the tank's got to come off. The pick-up strainer gets clogged up, and can't draw fresh fuel in from the tank. The swirl pot just recycles whatever comes back down the return line and sends it back up the feed. Any air that is sent back to the tank from the pump during priming comes straight back up the feed line. The problem is often worse just when the fuel light comes on, as at that level, the fuel is too low to dribble in through the swirl pot vent at the top of the assembly. A colleague took some photos when I took his tank off. If I can get them emailed across, they should help explain things a bit better.

[Ol'Jeffers]

Hi BB....Would you like to post those photos here, please?

[simoneg]

It might not be of interest to anyone this late in the day, but unexplained air in the fuel line means the tank's got to come off. The pick-up strainer gets clogged up, and can't draw fresh fuel in from the tank. The swirl pot just recycles whatever comes back down the return line and sends it back up the feed. Any air that is sent back to the tank from the pump during priming comes straight back up the feed line. The problem is often worse just when the fuel light comes on, as at that level, the fuel is too low to dribble in through the swirl pot vent at the top of the assembly. A colleague took some photos when I took his tank off. If I can get them emailed across, they should help explain things a bit better.

Found this old thread and as a result was able to get my local garage to recognise the cause of the problem as clogged strainer in the fuel pick-up - but not before they had unnecessarily replaced fuel pipes!  So many thanks to the forum for identifying this problem which is now resolved.  However, the garage did warn me that the tank seal might leak after removing the fuel pick-up as they say that the tank becomes distorted with age (my car is a 2003 model).  Brimmed the fuel yesterday and diesel fairly gushed onto the forecourt, so guess I will just have to live with the problem and avoid overfilling in future.  Anyone else had this problem after replacing the fuel pick-up?  Probably not an economic fix to replace the whole tank. 

For interest, cause of the blocked strainer is probably microbes growing in the tank.  My car does not get a lot of use so stands around quite a lot with a half empty tank.  So I am now trying a fuel biocide.  See for instance: http://www.bp.com/content/dam/bp-country...n-fuel.pdf

[Col]

For interest, cause of the blocked strainer is probably microbes growing in the tank.  My car does not get a lot of use so stands around quite a lot with a half empty tank.  So I am now trying a fuel biocide.  See for instance: http://www.bp.com/content/dam/bp-country...n-fuel.pdf

Trick is to leave tank full, especially in winter. Use Soltron to kill any diesel bug and be prepared to change your filter a few times.
Diesel bug lives in water at the fuel/water interface and will feed on hydrocarbon material including rubber fuel hoses. If you keep the tank full, there is less *space* for any condensation to form on the inside of the tank.

http://www.soltroniw.co.uk/