Injector pump

Can anyone please advise me, I'm pretty sure the injector pump cold start on my '87 90 2.5TD has packed up. Is this thing changable (if it is where is it and what does it look like) or is it part of the pump itself and I need to change the complete unit. Cheers

I would take the pump off and send it to be rebuilt, see if there is a lucas place near you could mail it to, or any good diesel repair workshop.

It is part of the pump but what makes you think it has packed up?

There is almost certainly a starting-up technique to follow which we tend to forget about, and as often as not this involves either FULL THROTTLE to start, or MORE COMMONLY, NO THROTTLE AT ALL.

The cold start devices alter the injection TIMING and sling in EXCESS FUEL but ONLY if two things:
1. the engine is turning very slowly, like at starter motor speed, and
2. there is no throttle pedal, i.e. the injection pump is looking at IDLE speed.

If your pump is like that and I think it will be, first make sure the glowplugs are in top class condition, and that they glow a decent time before you turn it over on the starter with the clutch pedal decked but NO THROTTLE. Just seeing the glow-light on the dash does NOT mean any of the plugs are actually glowing!

So, I reckon it's far more likely if the car runs fine, but is dismal to start is the glow plugs being a bit sluggish ... or perhaps one or two hardly working at all. These engine need a good glow to make them go!

As far as the pump goes, sling in a can of diesel cleaner when your fuel tank is very low, and take her for a drive. Sometimes works wonders.

CharlesY

Hi Charles Y, thanks for that, New short block just fitted, cylinder head pressure tested and re fitted, new Injectors, new glow plugs, new fuel filter.
always depress clutch, heater plugs for about 20 seconds and do not touch throttle until engine fires. It starts easily enough, but smokes badly for about 40 seconds slowly dispersing until all clear and is smoke free until I start from cold again. When starting when warm I get the usual puff of black smoke and then all seems ok. The cold start smoke is worse now than ever was. Vic

Thought they were all like that.

GRUNT said:

Thought they were all like that.

Click to expand...

Well Grunt I tend to agree there!

What he describes is POSSIBLY the result of a seldom troublesome syndrome caused by residual pressure in the injector pipes.

All the time the engine is running, the fuel in the injector pipes is under exremely high pressure, but not quite enough to pop the needle valve IN the injector except when the pump spits an extra slug of diesel at that pipe, which makes a shockwave in the column of oil that hits the needle valve and causes injection to take place. Fact is the pressure is there all the time - and then you switch it off and park up overnight.

The residual pressure is trapped in the injector pipes and injector body, but will eventually seep past the needle valve in the injector and drip into the cylinder, probably into the combustion chamber bowl in the piston crown. There could be about 2 to 3 ccs of fuel there. As soon as the engine fires up this liquid fuel gets blasted around and burned, but badly burned, and makes smoke. Once it clears, that's it until next time she's parked up overnight.

What do you think? Can you go with that?

CharlesY

Absobloodylutely though to be honest I'm just glad the feckin thing starts.

Thanks for that guys. Its just that I find it hard to accept that after all the work that has been done that the start-up smoking is now worse than before.
but thats Landies for you.
Vic

Thinking aloud here, were your injectors pre-calibrated or did you need to do them? If the injectors were not properly calibrated for your engine and the needle was not being held down as well as it should could this be the cause of the seepage?

Although I have to say they do tend to smoke a bit first start of the day, especially these engines. Its worse now that its colder too.

Hi Disco, to be honest I don't know- I ordered them from Paddock for my vehicle, but wether they sent the correct ones I don't know. Vic

I think they would be the right ones if they went in, however, its the question of calibration - if they are not correctly calibrated it could cause performance losses and higher consumption so might be worth a look, even if its not the direct cause of this fault.

It's probably a combination of a number of things, but the things that stop it are TIME and HEAT.

As soon as the motor is heated up, problem goes away.

This is fairly typical of diesels.

CharlesY