Dexta not starting

[gimiq]

Hello again,

It has been a while since i have looked at the dexta. Had to go back to the UK due to unwell family members.

it wont start.

charged the battery to full. It is a new battery installed last spring.

The Dexta was left in the poly tunnel. It was a hot summer. The same diesel is sat in the tank. I have bled the fuel lines up to the minimec bolts. there seemed to be a lot of air in the fuel supply system.

When checking the fuel flow on the line to the fuel pump it was flowing freely with a stream of about 3 inches distance. diesel tank is about 1/3 to 1/2 full.

when pressing the starter lever i see thin white puffs coming out of the exhaust at the usual rhythmic pace.

the starter seems to be turning over quite heartily.

during the cold start procedure i usually hold the starter lever down for between 7-10 seconds then stop holding it down for fear of burning out the starter motor.

There is an old chap who is the grand father of a friend who know his way around old tractors so probably going to get him to look at it.

but before I do, any advice or things to try?

thanks in advance

[Billy26F5]

Have you tried the heater and primer? It really makes a big difference. The starter should be ok on 30-40 seconds if you don't then use it again for a while, always worth making sure connections are good. As you have a minimec you have the luxury of an excess fuel button which is also worth using. The smoke coming out is a sure sign that fuel is injecting ok, Dexta's are never the best of starters as they have indirect injection. If with all this it doesn't start check the timing, but I would be surprised if it's that.
Sandy

[gimiq]

yes have tried the heater and primer cold start procedure as follows several times:

five initial pumps on the primer. can hear it spraying.
hold the heater element for 40 seconds, i hear a faint gargling noise coming from the air intake at around 20-30 second mark.
push down starter lever and hold it down whilst keeping the heater element button pressed and the clutch pressed. press the primer again after pressing the lever down (hear a noise when i do this, hard to describe, like a woompf from the air intake)

Tried it for a good thirty seconds a couple times at your suggestion.

the heater element is warm/hot to the touch after this starting procedure.

Still no go. after about thirty seconds i do hear the starter slow down a bit. will try and make a recording of it if it would help.

as for the excess fuel button, when i press it it just pops back out. doesn't seem to stick in like i would expect it to do after pressing it

[Billy26F5]

Sounds like the throttle is a bit low, set it at about 1000 rpm the button should stay in then and it might be better. With the primer you only need one before pressing the heater, then two or three times while turning over.
Sandy

[Hair Bear]

Normally, if you push the excess button, it stays in - unless you pull the engine stop - then it will pop out. If the excess button won't stay in, the engine stop control may be stuck and not be in the full run position. Check the movement at both the dash and pump end of the cable. Another possibility the engine stop was pulled a bit hard and it's 'jumped' the rack.

[gimiq]

I cant seem to get the excess fuel button to stick in wherever i put the throttle lever.

I started thinking perhaps there is still air between the pump and the injectors. as while there is thin whisps of white smoke coming through on cranking, they are so faint they are barely noticeable. So with no ideas left, i unscrewed these pipes that connect to the injectors to check. theres barely even a dribble coming out when i turn over the engine when pressing the starter lever. Seemed like a couple drops came out the first little pipe and didnt notice anything out the second or third. I was bracing myself with my goggles on .

how much should come out of here?

[gimiq]

seems to be the same problem as this person https://forums.yesterdaystractors.com/t ... m.1111015/

i loosened all three and only the third get a rhymthic spray/spit of fuel coming out of it when pressing the starter lever.
the other two seem to get barely a droplet forming out of them.

can get plenty of fuel to come out of the bleed screws on the pump itself.

nothing/barely nothing come out of the pipes to the injectors 1 /2 . excess fuel button not sticking in at any throttle position

the manual fuel pump pumps fine to the bleed screws

[Hair Bear]

The lack of fuel at the injectors together with the excess button not staying in still says to me the stop control is stuck, it's the lever that pivots on the excess button. It needs to be in the 10 o'clock position ie fully forward as far as it will go. The button should stay in regardless of throttle position, it's the pull stop/fuel cutoff that usually will not let the button stay in if it's not fully home.

[Billy26F5]

I see more issues here, the stop lever is the clear one, but the fact that only one is squirting fuel sounds more alarming. As for the throttle I would have said the same until a few weeks ago when I was sorting some of the linkage on Davie, during which the throttle lever on the minimec was sitting on the idling stop and the button didn't want to stay in. It does however at about 1000 rpm which is how we always start Davie and it works as well as it will with any Dexta. The fuel coming out of only one pipe could be poor injector pump calibration, but you need to sort the stop lever first to be able to see if it runs or not. If it doesn't clean round the inspection cover then remove it and check the rack is free, you must ensure no dirt gets in.Once you get the rack moving it should start ok, but if it sounds like one cylinder is firing different the pump needs to run in a calibrating machine. Probably worth checking the phasing too. If it sounds fine then leave it, some engines sometimes need odd things. Just thought you might have stuck plunger or tappet, the more I think the more likely it seems, Brian always recommended ATF to be added to fuel, also be careful trying to get the tappets or plungers or rack moving, don't unless the engine is in the correct position (the tappets and plungers will only move down when that cylinder is about to fire).
Sandy

[gimiq]

Ok thanks for the info. The stop lever is in the 10' o clock position.

The excess fuel button has never stuck in since the first day i bought it. Never thought much of it because it would start without needing it.

The dexta was working fine until i left it for about a year and came back to it this year and tried to start it with no luck.

I will upload a video of what I am seeing to show you better. (tried several times but upload keeps failing on my network, will get it up eventually).

I guess next step would be to remove the side cover plate on the pump and do what this chap did:

https://www.youtube.com/watch?v=jwTVEjGgNIs

trying my best not to get any grit or dirt in when i do it.

[Billy26F5]

That seems to be reasonable, the inspection cover retainer can be removed if needed (bolt just above inspection cover). Sounds like there are issues with that button, can you get it to stay in with higher throttle? Don't disturb any adjustments but measure the distance between rack forks, it should be almost the same, if not the pump probably needs more serious work.
Sandy

[gimiq]

I have not been able to get the excess fuel button to stay in under any condition. the throttle position seems to have no effect. from full to closed
nor with any combination of positions with the stop lever. I press it in and it pops right back out immediately.

is this the bolt i need to take off or is there more to it?
https://drive.google.com/file/d/1WrVMoc ... sp=sharing

will take video and photos of whats behind there.

when you say don't disturb adjustments. Should i still be looking to free up the stop lever mechanism like the video shown above?

the workshop manual i have only shows the older style pump. not sure the video i posted is the same pump either. So it is all going to be a bit of a discovery process

[Billy26F5]

The bolt is correct, the bolt immediately above will free the retainer if needed. You definitely have a problem with that button, but that's a different issue. The rack should move freely as in the video, there should almost always be a plunger at the bottom of its stroke, if not the tappet is stuck and needs freeing. When I say not to disturb adjustments I mean don't loosen any fork screws or similar. The manual on internet is only the original, a minimec supplement would have been published but it's not anywhere I've seen. The Major minimec is similar, it is covered in a supplement (https://www.fordson.se/2B_och_3_Br%E4ns ... 01-004.pdf) it's not the same but it gives you an idea of the internal workings.
Sandy

[Hair Bear]

Ah, sorry, just reread the trail...
As it's been stood a while I would go with Sandy's suggestion of a couple of stuck plungers. If you pop the cover off and wind it over you should see three moving plungers.
As a curiosity, have you tried tow starting it?
When our major arrived it had been stood for around 15 years. Unloaded it, made sure the crank moved, tied a rope to it and dragged it down the lane. It fired straight up although only running on one cylinder. Three stuck plungers in the pump. A couple of hours fiddling around to get them free and off it went. I can't remember exactly how it was done but I think side cover off, then four bolts on top and the top came off. No idea if the Dexta pump is assembled the same way though. Been running well ever since.

[Billy26F5]

I see you did a more drastic thing, not ideal as it risks more issues. The minimec has allen screws (six on a Dexta, eight on a Major) so it's not quite as easy to dismantle, I wouldn't take that off as it adds complications. The earlier Dexta pump is more similar to the contemporary Major one, even more similar to the Nuffield 3 cylinder one. If the plungers stick then the rack won't move much, if the tappets stick the rack will be ok but the tappets will need to be freed up. Freeing up plungers is more difficult and needs more care, as depending on how they stick it can affect the calibration. Tappets are much easier to get moving, although it is possible to damage the phasing spacer, this can be a bit of an issue too.
Sandy

[Hair Bear]

Oops lost in translation. I meant tappets not plungers!

[gimiq]

ok got it going. Seemed the rack was stuck it would close (go fully to the left) when i pulled the stop lever but would not go fully to the right when i pushed it the other way. used a screw driver to push it across.pressed the start lever and finally saw fuel come out of all injectors pipes at the point they go into the injectors. tightened it up. did the cold start procedure and it started after about 20 seconds of cranking. Big puffs of white smoke which settled down to transparent after 30 seconds or so took it for a little spin and sounded pretty healthy throughout. Need to remind myself which gears to use and what the proof meter should read when pootling about the yard.

it looked pretty rust free and in good condition in there. lubricated with a little bit of oil at the bottom of the inspection box, i presume that is as it should be

thanks again for all your help

[Hair Bear]

Yay! Well done - another one lives.

[Billy26F5]

Good stuff, looks like the rack cover end would have got stiff. I recommend you always leave it so the rack is at maximum fuel as then it should avoid this issue. Starting up regularly is the best solution though.Oil there won't do much, when you change the engine oil you need to change the oil in the pump too. The manual of the Major minimec should give you an idea of where the plugs are for doing this. Everything sounds encouraging, I suggest you try the button again, it should now work.
Sandy

[Hair Bear]

I had this happen on a TEF many years ago. The problem on that was the pull stop was pulling the pump lever just slightly too far. Once that was adjusted it then became habit at the end of the day to always leave it with the stop in and the button pressed ready to go next day. Still do it today with machines with a pull stop, and the button as well if it has one.
Take it for a spin on a regular basis. The best time to do this is when 'management' want's to go shopping. Let 'em go, this preventative maintenance is far more important.

[Billy26F5]

Very right, I never leave the button pressed but rarely leave the stop pulled out (if I do it's only for a few hours at most), it must however stay pulled out if not pushed in again (legal requirement). Frequent running is always best.
Sandy