injection issues

[mikep]

Hi
Got a problem recommissioning my old B414. It's been a nightmare as everything you come to is knackered or needs overhaul. However now the mechanical side is fine I now have a fueling problem.
It's not fueling because although if you take an injector pipe off it spurts fuel on cranking there is not enough pressure to work the injectors. The injectors are clean and free so it's a pump problem. The fuel in the pump was clean and free from water so could it be a stuck rack? Any suggestions out there TIA.

 

[agrimax]

If it has an inline pump, take the side plate of and see if the rack is moving freely throughout its full travel. If it's a rotary cav pump, there should be a filter under the fuel inlet pipe fitting. Could be dirty and not letting enough fuel through.

 

[mikep]

CAV rotary. Filter clean, vanes on first stage rotor look OK. Lift pump supplying plenty of fuel just not injecting
Unfortunately I'm at the stage where I must continue because of the time and money spent already otherwise it could go back into the friggin hedge.

 

[agrimax]

I would then say that the metering valve lever is stuck. Needs the lid off the pump.If you're not familiar with under the lid,the governor spring needs detached(must remember which holes it reattaches to) to get the lid right out of the way.Then there is a flap or control arm with a long bar surrounded by a spring which connects to the metering valve lever. I'd guess this lever needs freeing.No.42 below.

 

[mikep]

I would then say that the metering valve lever is stuck. Needs the lid off the pump.If you're not familiar with under the lid,the governor spring needs detached(must remember which holes it reattaches to) to get the lid right out of the way.Then there is a flap or control arm with a long bar surrounded by a spring which connects to the metering valve lever. I'd guess this lever needs freeing.No.42 below.

Thanks. Took top off and the arm is free in the body.
Stop is engaged in the arm so not sticking. May be new pump time or back in hedge. New B414 cylinder head for sale time I think.

 

[Mur Huwcun]

Have you tried tapping the pump just in case tye plunger is sticking? Although nit ideal have you removed an injector and connected to a pioe and crank the engine to see if it atomises at all? Otherwise try a tow start (engine will turn over faster) or a whiff of drugs!! Of all the ones I’ve rebuilt or resurrected they never seem keen to start on the first startup and a tow usually coax them to life!!!

 

[agrimax]

So the metering arm/valve is definitely free to turn as well? Maybe worth leaving the pump in to a repair shop?

 

[Mursal]

An the gauze filter under part 48 in the above diagram is spotless?

 

[Still Farming]

Is pump lever running on cam ok.
Is fuel line all clear from tank to filters to pump everywhere?

 

[mikep]

All filters clean. Fuel coming freely from the lift pump through bleed nipple on pump. Tried a tow before but may give it another go as nowt to lose.

 

[Mursal]

If you line up the timing marks you should be able to "just" put a copper wire strand into number one injector outlet. Measure how far it goes in with the engine away from the marks and then repeat coming to the marks. This will show the drilling in the injector pump shaft has aligned to fire on number one.

 

[TheTallGuy]

Bundy Bear on YouTube has a good video on rebuilding the CAV pumps - I think it's this one

, although he has a couple of others covering it as well.

 

[mikep]

Bundy Bear on YouTube has a good video on rebuilding the CAV pumps - I think it's this one

, although he has a couple of others covering it as well.

Think I will get a kit off eBay and give it a strip and rebuild. Getting pee'd off at present with the lack of progress.

 

[X344chap]

Had the exact same problem. Plungers were sticking in the bore with sitting so long. took the pump apart and cleaned plungers with some toothpaste and it went perfect after that.

 

[Mursal]

Colgate?

 

[mikep]

Had the exact same problem. Plungers were sticking in the bore with sitting so long. took the pump apart and cleaned plungers with some toothpaste and it went perfect after that.

Colgate?

Kit ordered so a strip and clean and will probably use Sensodyne as it sounds like a fuel pump part and fills small cavities.
Actually prefer to use T cut on stuff like that as its a more regulated abrasive toothpaste can be a bit coarse but it does give fresh breath confidence all day long. I wonder if you used Eucryl it may stop it smoking (If you get that you're bald or grey)

 

[X344chap]

DPA manual is available on the internet and its much more simple than you think to strip down and clean. Take pics of everything and note the metering position on the end plate of the hydraulic head. On the ones i've seen there is brown staining marking the position. This metering controls the amount fuel delivered on each stroke of the pumping plungers.

Mine was exactly as you described - if you cranked the engine then you got fuel squirting from the injector pipe to injector union - but when you nipped them up and tried to start the engine there was no smoke from the exhaust. The pump just wasn't developing enough pressure to open the injectors The strip down and clean of the pump plungers (i think i replaced the rollers and shoes as well as there was some flatting marks on the rollers) was all that was required to get it perfect again. You need a special key to remove the two bolts holding the metering plate.

Eucryl to stop it smoking - i like it !

 

[JeremyD]

Kit ordered so a strip and clean and will probably use Sensodyne as it sounds like a fuel pump part and fills small cavities.
Actually prefer to use T cut on stuff like that as its a more regulated abrasive toothpaste can be a bit coarse but it does give fresh breath confidence all day long. I wonder if you used Eucryl it may stop it smoking (If you get that you're bald or grey)

Did you ever get it going? I've just put new liner and piston in a 444 I got off ebay, but can't get it to quite run. Fitted new injectors but I think fuel pressure is too low to open injectors properly! Barely runs for few seconds then dies!

 

[Will 1594]

Did you ever get it going? I've just put new liner and piston in a 444 I got off ebay, but can't get it to quite run. Fitted new injectors but I think fuel pressure is too low to open injectors properly! Barely runs for few seconds then dies!

Will send you a friends number ,who has a load of old nash ,and has restored some right wrecks ,he kows how to fettle them ,if you have no joy

 

[JeremyD]

Will send you a friends number ,who has a load of old nash ,and has restored some right wrecks ,he kows how to fettle them ,if you have no joy

Thanks. Will have a fettle with pump, I suspect something partially seized everything else was full of water!