Dexta not starting

[Philo]

My Fordson Dexta will not start. The start engine is running happily, turning the fan like it should, but the diesel engine will not start. I’m not sure what to try next.

Background: This winter I realised that the fuel tap under the fuel tank was leaking a lot, so I ordered a new one from a parts seller in Sweden. The one I recieved didn’t look like the old one. The new one only has in and out connections and a turning knob while the old one also has a primer button and an output for the “40 sec” heater/manifold connection. I asked the seller about this and they told me that the new tap was the right one and that they had never heard of the thing on my Dexta.

So I removed the old, leaking tap (unfortunately accidently breaking it beyond repair during removal) installed the new tap and plugged the hole on the manifold where the cold start fuel pipe used to connect, using a bolt and some tape. I have also changed the oil and fuel filters, cleaned the air filter (put it in a bucket of diesel over night) and followed the Dexta manual’s instructions for getting air out of the fuel system.

Only then did I start making proper research, beginning to learn about the primer/cold start functions on the old tap - which I have never been aware of or used before.

My questions:

1. Is the fuel pipe connected to the manifold (which I removed and plugged) necessary for the tractor to start, even in summer? If yes, can I solve this whithout the old tap, even though the new one doesn’t have a connection for this pipe.

2. Do you have any suggestions about what to check or try next, to start the tractor?

Being a beginner - and Swedish - I hope for some patience if I don’t understand all the necessary technical terms right away, or don't use them correctly myself.

Grateful for any advice!

[Billy26F5]

The engine should start, but when cold, it will struggle. The Dexta is an indirect injection engine, so don't expect it to start in two turns even hot, as you would with a Major. That said, when cold it's well worth having the primer and heater as it speeds up starting a lot (5 secs instead of nearly a minute turning). Your seller has sold you a Major tap, he might have confused the Dexta with the later Ford worldwide light tractors. New taps are available but make sure it's a Dexta one with the primer. I would return the Major tap and use the old one for now. You might find that changing the O ring in the tap will seal it fine.
If you have a minimec (as in the pic) press the excess fuel button as well as that helps too (the one with the rubber on the stop lever).

Sandy

[Philo]

Thank you for your input!

I have used this Dexta for five years without knowing it had the primer function. Sometimes it has been a struggle to start it, but not like this. I am afraid I broke the old tap into two pieces while I removed it so I can't put it back. When I look for "Dexta fuel tap primer" on the Internet, this model appears in a lot of places:
https://www.sagro.se/sv/artiklar/branslekran-dexta.html
It doesn't look excactly like my old one either, though. This one seems to have only one output - I guess there must be two, to feed both pump and manifold? The old one had two outputs.

Excess fuel button sounds like something worth trying. I don't find it in your picture though. Perhaps I misunderstand where to look for it? I was also looking for it in the manual but it doesn't mention it.

[Billy26F5]

The Dexta manual might not mention it, if you pull the stop knob, you'll see the stop lever move on the pump, the button inside the shaft on the stop lever with a rubber cover is the excess fuel button.

I recommend asking these people about their tap, it looks all right but I can't see the primer outlet in the view they've got.
Sandy

[Philo]

Oh, got it. Mine doesn't look the same. I'll post a picture as soon as I learn how.

I find this primer tap on many sites, with pictures at different angles, but there doesn't seem to be any separate primer outlet:

https://images.app.goo.gl/9wx4HXaULdP8HXFY9

So what happens then, when the primer button is pushed? The pump gets some extra fuel? Do you think that would help my Dexta?

[Philo]

Asked the seller about outlets, and got a picture from another angle, showing a hole on the other side of the primer button - for connecting a pipe to the manifold!

[Jerry Coles]

Photo of Dexta starting cup.

Code: Select all

https://drive.google.com/file/d/10cspy8zcdDwnEDkybY83CZVc9J8sf6Wq/view?usp=sharing

Jerry

[Jerry Coles]

[Billy26F5]

That heater seems more expensive to use!
Sandy

[basewindow]

My Super Dexta doesn't have the primer, obviously removed sometime in its past. I've never had an issue starting it, but it doesn't get too cold here.
Are you sure you've bled the fuel system properly?
Are you getting any smoke out the exhaust whilst cranking?
The primer squirts a bit of fuel up into the intake where it is heated by the glow plug and helps starting in cold conditions.
Regards
Cam

[Philo]

Well I used to have the primer, but never used it since I wasn't aware of the function. I don't think the previous owner used it either, because when I asked him about the fuel pipe between the tap and the glow plug he didn't know what it was for.

No, I'm not sure I bled the fuel system properly. I will give it another try.

Yes, I see white smoke puffs.

Thank you for taking the time.

[Philo]

Photo of Dexta starting cup.

Code: Select all

https://drive.google.com/file/d/10cspy8zcdDwnEDkybY83CZVc9J8sf6Wq/view?usp=sharing

Jerry

Interesting. What is a starting cup?

[basewindow]

Sounds like you haven't bled the fuel system properly.

Do you have the manual outlining the procedure?

From memory...

Start at fuel tap, make sure its on.
Loosen inlet as lift pump and make sure fuel in coming out. Tighten.
Loosen at outlet, check fuel it coming out using manual pump if necessary. Tighten.
Fuel filter, loosen bolt on top. Pump manual pump at lift pump until fuel flows out. Tighten.
Follow outlet to injector pump. Loosen connector. Manual pump until fuel comes out. Tighten.
Loosen each fuel line connector in turn on injection pump and pump/crank until fuel comes out if each. Tighten.
Do exactly the same at each injector.
Once you have a nice flow of fuel coming out at each injector, tighten.

Now attempt to start. It may take a bit of cranking, but it should start to fire as each cylinder gets fuel.

Repeat if you can't get a start.

Regards
Cam.

[Billy26F5]

Don't turn the engine until there's only fuel between the tank and the injector pump. Don't pump the lift pump when there's any leak on the feed pipe, tighten it a wee bit and check it has stopped leaking, or you'll be sucking air.
If the lift pump doesn't seem to pump anything turn the engine one revolution and try again.
Once bled use the heater and primer to speed up starting.
Sandy

[basewindow]

Edited above cheers Billy. My Dexta and manual are up at the farm, in lockdown in another location. COVID sucks.

[Bluebilly]

A few years back, the diaphragm on my cold start priming button failed and caused excess fuel to go into the cylinders when stopped, causing it to hydraulic. I replaced this button pump with the type you have fitted and also fitted the cold start system similar to a MF35 (Auxiliary fuel tank Agriline Pt No7127). I can't remember where I got the kit from, but it took no time to fit and works like a treat. Since I renewed the lift pump I hardly need it anyway.

[Philo]

Many thanks for all advice! As soon as I get an hour off I will start the bleeding process all over. Update coming...

[Philo]

So... bleeding again. Now I see fuel pouring out at the bleeding bolt on the injection pump as I push the manual pump. If I tighten it and open one, or all three, of the outlets on top of the injection pump, I see fuel ready to enter the pipes leading to the injectors, but there is no movement here if I push the manual pump. Conclusion?

[Old Hywel]

Using the hand primer pushes fuel into the injection pump, not through it. Should at least smoke now, if cranked.
Not a good idea to completely remove injector pipes, too much chance if bits getting in.

[Philo]

Ah, will keep that in mind. Anyway, now we are running again!
This was a fantastic learning experience. Thank you all so much for your kindness, sharing your knowledge. Me and Dexta have now reached a new level in our relationship...

[basewindow]

Glad she's running again.