I have a 1996 Disco 300Tdi coupled to a four-speed ZF autobox and it’s dif cult to fire up. I’ve changed the glowplugs and tested the wiring. Every now and then she misfires, leadin me to clean the tank, replace the fuel lines, bypass the sedimenter and put a bowl under the bonnet, and she still misfires. The other day I started the car and she wouldn’t rev for 30 seconds.
Chris Webster, Croydon, Surrey
This does sound like the fuel system is letting a small amount of air in and the car is having to purge it before it will start or run properly. Check all the fuel lines and fuel lift pump. You’ve already bypassed the sedimenter, a common area for air leaks. I would fit a new sedimenter as it collects sediment and water from the fuel tank on the way to the filter. The part number is NRC9708 and it’ll cost you about £25. Also check the fuel sender unit at the tank – the pipes on these rot out and can allow air into the system.
This workshop advice appeared in the March 2015 issue of LRO. Back issues are available to download on digital devices here.