Two Citroëns, two problems
I am writing regarding issues with my two Citroëns. The first is with my 2006 Citroën Berlingo 1.9 diesel. It has 125,000 miles on the clock and has developed cold starting problems. When starting from cold in the morning, I need to pump the accelerator and allow the pre-heating light to turn off two or three times before the engine starts. When it finally starts, it is very smoky and there is a smell of diesel coming in through the heater blower. After a few minutes it settles down, runs OK and the smell disappears. The fuel filter and oil filter are replaced every 10,000 miles and the air filter is cleaned regularly. It has had new glow plugs fitted and received a boost of injector cleaner to the diesel, but now my mechanic is going to try a non-return valve.
The second problem is with my 1965 Citroën AZU Fourgonntte 725cc with a reconditioned engine, which seems to be backfiring. A hole in the exhaust has been repaired professionally and it has been fitted with new barrels and pistons, a new ignition coil and new plugs. Yet when I am driving it, it still coughs and splutters, especially when taking my foot off the accelerator pedal or reversing. The other day on a five-mile run it made a bang like someone firing a gun. What do you think could be causing these symptoms? Richard Muller
Regarding the Berlingo, as you have had the glow plugs replaced, I assume that they are operating correctly. However, as a precaution, I would check the voltage at each plug, just to ensure you do not have a connection problem.
I am assuming that your mechanic is fitting a non-return valve because he suspects that the fuel may be flowing back when the vehicle is left. This can be checked by attempting to hand-prime the fuel system before starting up.
Having eliminated the heater plug system, the next likely cause of the poor starting is either the fuel leak-off or return pipe. Check these for any damp spots, which would indicate a leak. Any leak in the pipe will allow air to enter the system when it is not running, causing the poor starting you are experiencing.
With regard the AZU, there are quite a few possibilities and the basic service items should first be eliminated. The valve clearances should be checked to ensure you do not have a tight tappet, which could cause the valve not to close fully. You should also check the points’ gap and ensure the dwell angle is set correctly. If you have not already done so, I would replace the points and condenser as a matter of course. It is better to replace the points and condenser than to adjust up a worn set of points, because if they do develop a problem they are not easily accessible.