Fordson Dexta Ran Away, Now What?
 

Gdayteam, thanks for your time in reading this.

I have a 30ft wooden launch that has a late 50s/early 60s Marinised Fordson Dexta in it.

The engine is used for approx 2hrs per month.

It was blowing a lot of white smoke a few weeks back and I pulled the injectors and sent them away to get refurbished.

Yesterday I recieved my cleaned up injectors back with new nozzles on them.

I installed them this morning and started the engine up. It went fine, started easily and idled smoothly for about 10 min there was some white smoke but nowhere near as much as previously.

After 10min I noticed the revs were not steady anymore (by ear, no tacho) they had a surging rhythm.

I was checking the injector seat bolts when suddenly the revs starting increasing quickly I pulled the stop lever to shut off the fuel at the injector pump and it didn't stop the engine was now revving very high.

I knocked off the air cleaner and blocked the intake with a piece of wood and the revs came back down to a normal range but the engine still wouldn't stop.

I undid all 3 injector lines while holding the wood over the intake and it still wouldn't stop.

There is a breather from the crankcase to the air intake and I was in the process of undoing this to block it when the engine finally stopped. It ran for 3-4minutes after I disconnected injector lines.

It stopped like it normally would not seized or anything making major noise from inside.

...........

Whats next?

How do I figure out the cause?

What should I check for damage?

My rings haven't been showing sign of wear, ie no black/blue smoke.

I can only think it has something to do with the recent injector replacement. But then it ran for 3-4 min after I disconnected the injector pipes. So must have been getting 'fuel' from the crankcase breather.

Any ideas?

Any and all help very much appreciated.

these things were fitted with a perkins motor there are two the only difference between them is the cubic feet

check the lift pump, that should be on the left side of the tractor (from front) the way to bleed these things is by unscrewing the 2 bolts that are on the fuel filter and pushing the primer located on the lift pump, you keep priming intill nothing but diesel is coming out
check the vavle lash should be .010"

there should be a little tag, front right side if you are looking from the front, remove that and see if the timing marks line up( you will have to rotate the engine to see)


there is a filter capsule on the injection pump, that is sopposed to be clean, this would cause a major loss in power and could keep it from firing, these things also have a pneumatic governor, this would also cause failure

when you put the new injector in did you see if the copper washer came up with the injector, if not, it is still seating inside the head and when you put new injetor in, it should have come with new washers and you could have set the injection tip protrusion to high.

I will go through my library and see if I can pull anything on this.

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this is a start

if there is no fuel at the injection pump, check for air, if there is no air, check the filter, if the filter is clean, check the lift pump, if the lift pump is ok, check the tank vent, make sure it is not blocked, if there is fuel at the pump, check the control rod, if it is not the control rod, it is your injectors.

with all of this, we are saying that there is nothing mechanical, if it is mechanical just post back and ill try to find my books.

Thanks for taking the time to reply.

Could be the copper washer, I am going back to have a look tomorrow.

Will let you know how I get on.

Well I pulled the injectors out again and unfortunately there wasn't any extra washers in there.

There was oil dripping out of the air intake, so until I figure out where thats coming from I'm not game to start it up.