Tractor heritage, news and features

Star letter: Diesel dilemma?

Some years ago, I managed to fix (got lucky again!) a similar problem on a restored Fordson Major diesel which would run for short journeys okay (up to say five miles) but would occasionally cut out on longer journeys. After checking fuel levels/bleeding etc. all would be well.

I eventually traced it to a blocked fuel cap vent – the enthusiastic restorer had sprayed over the fuel tank cap with so much paint, air could not get into the tank and a vacuum was forming. On short runs the lift pump had enough suck to overcome the vacuum but on a longer run, the vacuum would increase until the lift could no longer draw fuel. Also, there is then atmospheric pressure acting on fuel unions so if one isn’t quite perfect, air will get into the system.

This may not be the cause of your problem but it may be worth a look if the problem persists.

Dave Pearce,
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