JCB 3C fuel injection pump woes

[mgallo]

HI all,

I had posted a while back regarding this backhoe and eventually found the problem to a loud rapping noise - the flex plate had broken, most likely because the last person did not torque the bolts to the right setting.

Well I have had the head and injectors re-built, and put in new sleeves and pistons and rod bearings as there was one piston with broken oil ring and since it was out of the unit....

The fuel injection pump was not removed from the engine.

I used the mechanical pump to fill fuel filter.

I attempted to start it and the engine revved - person helping me put the throttle cable on wrong side of shaft. Immediately shut off fuel and turned off.

Moved the cable to proper location and the unit ran for a short while then slowly died, as if it ran out of fuel.

SInce that time haven't been able to get it to run.

It will run on ether squirted into intake.

I have loosened up the bleeders on the fuel injector pump and cranked the motor until fuel came out. I also loosened up the injectors and waited until I saw fuel drizzle out.

But the return fuel line on the back of the fuel pump loses fuel as soon as I start cranking.

I can open up bleeder on fuel filter and pump fuel with mechanical pump and I can remove all air in the filter.

The mechanical pump works well, if I crank over I see plenty of fuel being squirted.

I have a few questions, when you crank and bleed out how long should it take to remove the air from the pump? If I stop cranking and then shut the screws does it allow air in or do you have to shut them while you are cranking?

Do you have to loosen all four injector lines, and if so how long should it take to push out all air?
How should the fuel be coming out of the lines, shooting or drizzling?

I have included a pic.
A is one of the bleeders, B is the second one (on back of pump)
C is the throttle, right now would that be in the idle position?
D is the shutoff, is that in the open position as seen in pic? I know he took off the top lever and I am sure it is seated on the shaft now. I think this is the open position?
E is the line that I believe is the return line. I can pump the mechanical fuel lift pump and fill it but as soon as I start cranking the fuel seems to get sucked back into the pump.

[agrimax]

Throttle is in idle position. Shut off lever is in run position.The pipe you say is the return is not.It is the feed to the pump.Are you also sure that the pipes on the fuel filter are correct? Don't follow why the top bleed screw is on the back of the top cover.Normally found facing out above the bottom bleeder,but shouldn't really matter it's location.When you have the pipework sorted correctly and fuel at both bleeders,slacken all 4 injector pipes and crank over.Should have a good supply at each.Tighten up no's 2,3,and 4 and crank with 1 left open.(No 1 at fan end).Tighten up 1 when it starts.

[Stormin]

Have you tried with the fuel shut off lever in the opposite position to that shown? It is not unknown for them to be connected in the wrong orientation when a pump is rebuilt.

[chainmaker]

Hi hope you don't mind me throwing my twopeneth in for what its worth,Aggrimax is correct in saying the fuel pipes are wrong if when you have tried what he says do the following undo all the injector pipes at injectors move them away from the nipples and get some one to crank engine watch the injectors if one of them blows air out of the nipple thats the problem the injector needle is stuck and it will never start (this goes for any engine fitted with a dpa pump inline pumps will run but missfire) if thats ok on top of the pump you will see two nuts that are wired together these hold the top of the pump on remove throttle and stop cables remove the nuts and lift the top up a little beware of the gasket look under the lid and see if the internal springs are still connected the usual problem was the stop spring broke the end off you can change the springs but its a fiddle and you must get the throttle in the right hole. Or you can remove pump and do it on the bench I used to chang them in sitchu
brgds ron