JCB 3C runs 1 minute and dies

[mgallo]

Hello folks.

I have a Jcb 3CIII with a Leyland 4/98 engine and a CAV fuel injector pump. We re-built motor but did not remove pump.

Initial start-up the engine revved up and then died.

Had a few issues with lines, fixed all of them. prime pump, bleed lines, injectors.

See good fuel out of injectors and return line.

Here is the problem.

It runs for 1 minute and then dies.

Can start back up again almost immediately and then it also runs for 1 minute and dies.

No air seen in lines.

Can something have gone wrong internally on pump?

I'm stumped.

Any help would be greatly appreciated.

[agrimax]

Firstly,try running a gravity feed supply from a drum of diesel set up higher than the engine.Feed the injector pump directly from the drum,bypassing the filters and lift pump. If the problem persists,you have a pump problem.If not,chances are there is still an air leak before the pump. Would also check the nylon filter in the inlet end of the inj pump is clean and that the regulating piston is sliding free inside that end too.

[mgallo]

I will try to gravity feed with some fuel.
For your other suggestions, do I need to remove the top cover of the pump in order to get to the filter or the regulating piston?
If so what other precautions must I take?

[agrimax]

No.The cover does not need to be removed.The fuel inlet pipe goes into the pump(the end where the injector pipes come out),through an adapter,underneath which is the regulating valve,filter,piston and 3 springs.24mm spanner removes the adapter nut and it's a matter of fishing the rest out below it.It is VITAL that these parts are put back in the correct order or the engine will not go.May be easier to remove the end plate of the pump which contains the parts.Easier dismantling and refitting on the bench!

[v64paul]

Try the lift pump first, Depending on the type there used to be a filter/gauze under the domed cover on top of the pump.