2.5 NA 12J Hard to Start

[jrjackso]

I have a 1986 defender 90 with a 12J 2.5L NA diesel. It seems a little stuborn to start. I hold the ignition for glow plugs for about 10 seconds, then it takes about 10 seconds of solid cranking before I'm rewarded with a puff of smoke and it's running. Any advice? Or is this normal for this engine.

thanks

jeff

[Ash.Witty]

I would say there is a fault with your glow plugs, mine was like that till I fit a new set then it fired up like a dream.

I checked mine by removing, reconnecting the wire and by grounding the body of the plug to the engine then flicked the ignition switch on for a few seconds and it should glow red hot. If not they're broken and need replacing.

[Eightpot]

10 seconds isn't that much on these engines actually - from cold they need around 20-30.

If that still doesn't help then check connections to the glow plugs and replace the plugs.

[Ash.Witty]

Don't know about that, seems a long time cranking mine used to fire up pretty instant.

[Eightpot]

Exactly - give it long enough on the glow plugs and it should start with hardly any cranking.

New plugs will likely make a big improvement though.

[jrjackso]

I pulled all 4 glow plugs and tested manually by directly connecting to a power source and each one glowed red hot in about 7-8 seconds. Test light shows glow plug wiring is hot when ignition held in glow-plug position. So i'm thinking it might not be the glow plugs. Any other recommendations?

[Paddy]

Same engine as yours, 10 seconds at most on glow and it starts imediately at this time of the year.

Maybe injector service needed or diesel leaking out of injector supply line back to FIP and requires some cranking to get diesel to injector nozzle.

[Snagger]

It won't be the glow plugs. It's the fuel side - the pipe work will be allowing air in when the engine is shut down, allowing fuel to drain back down to the tank and requiring the injection pump and injectors to be re-purged on each start. Check every union is undamaged (the olives can wear out from vibration or over-tightening) and are suitably tight. Inspect the injector pipes for small cracks and replace the leak-off pipe copper washers and look for pin holes in the plastic piping. Check the seals on the fuel filter, too.

[jrjackso]

Thanks Snagger. There is a series of rubber tubing between the injectors that looks like a return line. Is that what you are calling the leak-off pipe? One was split where it fit over the nipple and looks like it was leaking a little fuel. Will replace. Assume I will probably need to purge the system? New to the defender so thanks for the pointers.

[Snagger]

That is indeed the leak off pipe. Any air leaks in the system will allow the fuel to drain back down when shut off. Replacing that pipe may fix the problem, but if not, look for more leaks. The trouble is that a leak can be small enough to prevent fuel getting out but permit air in, so if replacing all the leak off hoses (they are notoriously prone to perishing on Tdis), then inspect the rest of the pipes systematically until you find the fault(s). Olives on the plastic pipes into the lift pump are another common source of leaks. The system will self purge as long as you have a return line to the tank (standard, but some people loop the return into the lift pump feed as a bodge for a leaking return line or when fitting a vegoil fuel system with heat exchanger, which is fine as long as the system is 100% leak free as self purging no longer occurs and air will build up until the engine cuts out).