Ford Dexta issues.

Hi all, a mate has bought a 3 cylinder Ford Dexta (late 60's?) which was supposed to be "running when parked".
It does run, but takes forever to rev up and knocks hard and blows lots of black smoke as it does. Sounds OK once the revs are up. Once in gear, it can barely pull its own weight. It has a rotary injector pump. The exhaust seems clear and disconnecting the air inlet makes no difference. It is running on all three - the revs drop markedly when any line is cracked.

Any ideas?

Thanks, Jarrod.

Tell him it’s stuffed and I’ll take it off his hands

No I’ll be serious now first thing I would try is moving the timing back a little bit . I don’t know what they have to adjust them with a rotary pump the super maj ors with the inline pump have an adjustment on the drive coupling

Cheers Bluey

The DPA pump has a very fine plastic screen inside the big nut on the top of the hydraulic head end plate ..that is the first thing I check.........be careful removing the nut because there is a small valve and spring inside that can drop out and be lost..........Another  possibility is the timing is a long way  retarded  , maybe explain the power loss.

DPA pumps also usually have an advance /retard device on the undeside of the aluminium body ,but Ive never known one of these to malfunction.

Its also possible the pump has air in it ,but that usually causes the engine to stop after 10 seconds or so .......if the injector lines have been purged ,and the engine run ,then I d say there is no air .

Sounds like the governor isn't working
Does this have a separate compartment for the governor that is meant to have oil in it,the fly weights won't work properly, or maybe it doesn't allow the rack to slide without the oil

But it does sound like something there

Paul

Jarrod, you mentioned checking the exhaust.
Was that for carbon build up?
Early small farm diesel tractors needed regular decoking unless worked hard at higher temperatures. A day plowing, driving a hammer mill or PTO baler usually did the job.
Amazing amount of carbon deposits out the exhaust once they got hot at full noise.
May not be the problem of course.

Worst problem I ever had with a DPA was from using waste aviation kerosine .........trace of water in the tank ,and fuel fungus went wild ..........seems fungus loves jet kero.,which is probably why its discarded after one month storage.

I had to pull the pump apart every time I wanted to use the tractor ...which was generally a council notice withh 14 days ..

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