Super Dexta Diesel Combustion Issue

[jlowe14]

Have a ‘63 Super Dexta with 3cyl Perkins Diesel. Converted to 12v. Recently replaced solenoid and ignition wiring. Engine will turn over but will not fire up and run. When starting, no “smoke” from exhaust manifold, just small puffs of vapor (assuming fuel/air mix). Unsure of what to check first to try and fix. Any advice?

 

[Majorman]

Have a ‘63 Super Dexta with 3cyl Perkins Diesel. Converted to 12v. Recently replaced solenoid and ignition wiring. Engine will turn over but will not fire up and run. When starting, no “smoke” from exhaust manifold, just small puffs of vapor (assuming fuel/air mix). Unsure of what to check first to try and fix. Any advice?

First thing, you do not have a Perkins engine in your Super Dexta!!!! The engine is a Ford design which was assembled by Perkins who then used some of the ideas on later engines they made. I say this, not to be difficult but to make it clear that Perkins parts will not always fit when it comes to spares. Second thing, your tractor has not been converted to 12 volts, it left the factory like that, 12volt Positive earth. Now to your problem, sounds like you are not getting diesel into the cylinders. Have you got a good flow of diesel from the tank to the lift pump? Have you changed the fuel filters? Have you bled air out of the system? If the answer to all these is yes, does your pre heat device work and the primer pump in the fuel tap function? Do you heat for 40 secs then give a couple of squirts on the primer button, listen for the "Pop" and then press the starter?

What type of injection pump do you have? Vacuum governed or MiniMec? Some Dextas with Vacuum pumps were badged Super Dexta by dealers in the US.

Lots of questions but we cannot see your tractor and need this sort of information to be of help.

 

[jlowe14]

First thing, you do not have a Perkins engine in your Super Dexta!!!! The engine is a Ford design which was assembled by Perkins who then used some of the ideas on later engines they made. I say this, not to be difficult but to make it clear that Perkins parts will not always fit when it comes to spares. Second thing, your tractor has not been converted to 12 volts, it left the factory like that, 12volt Positive earth. Now to your problem, sounds like you are not getting diesel into the cylinders. Have you got a good flow of diesel from the tank to the lift pump? Have you changed the fuel filters? Have you bled air out of the system? If the answer to all these is yes, does your pre heat device work and the primer pump in the fuel tap function? Do you heat for 40 secs then give a couple of squirts on the primer button, listen for the "Pop" and then press the starter?

What type of injection pump do you have? Vacuum governed or MiniMec? Some Dextas with Vacuum pumps were badged Super Dexta by dealers in the US.

Lots of questions but we cannot see your tractor and need this sort of information to be of help.

Thanks Majorman… I’ll be out on the farm later today and will check the fuel system as you suggested… as for the preheat device, I really don’t think it has one. There’s no switch or button to engage one. I’ll follow up later with some details on the fuel system inspection. Thank you sir!

 

[Majorman]

Thanks Majorman… I’ll be out on the farm later today and will check the fuel system as you suggested… as for the preheat device, I really don’t think it has one. There’s no switch or button to engage one. I’ll follow up later with some details on the fuel system inspection. Thank you sir!

All Dextas have, or should have a large button on the dash panel on the right of the rev. counter. They should also have a plunger button on the side of the fuel tap. On a MiniMec pump, there is also a cold start button in the centre pivot of the stop control. Pull the throttle about a quarter open and push the button in, it will lock and should fly out when the engine starts.

 

[jlowe14]

All Dextas have, or should have a large button on the dash panel on the right of the rev. counter. They should also have a plunger button on the side of the fuel tap. On a MiniMec pump, there is also a cold start button in the centre pivot of the stop control. Pull the throttle about a quarter open and push the button in, it will lock and should fly out when the engine starts.

 

[jlowe14]

First thing, you do not have a Perkins engine in your Super Dexta!!!! The engine is a Ford design which was assembled by Perkins who then used some of the ideas on later engines they made. I say this, not to be difficult but to make it clear that Perkins parts will not always fit when it comes to spares. Second thing, your tractor has not been converted to 12 volts, it left the factory like that, 12volt Positive earth. Now to your problem, sounds like you are not getting diesel into the cylinders. Have you got a good flow of diesel from the tank to the lift pump? Have you changed the fuel filters? Have you bled air out of the system? If the answer to all these is yes, does your pre heat device work and the primer pump in the fuel tap function? Do you heat for 40 secs then give a couple of squirts on the primer button, listen for the "Pop" and then press the starter?

What type of injection pump do you have? Vacuum governed or MiniMec? Some Dextas with Vacuum pumps were badged Super Dexta by dealers in the US.

Lots of questions but we cannot see your tractor and need this sort of information to be of help.

Update… thanks for the assistance Majorman. Bled the fuel system and drained the injector pump oil and refilled. Started right up and running smooth now.

 

[Majorman]

Update… thanks for the assistance Majorman. Bled the fuel system and drained the injector pump oil and refilled. Started right up and running smooth now.

What are the buttons/switches for on either side of the rev counter? Someone has been messing around with the wiring but if it still works, that is fine. The silver one should be the push button heater switch. You are very lucky if she starts OK, even in our mild climate here, a Dexta or Super Dexta will still need a bit of heat to start from cold.