Strange starting woes - two separate issues?

[mmgemini]

I don't remember a problem with loose leak off pipes..Only diesel all over the place.

I too would wire the heater plugs up. Even if only temporily with a switch and relay.

Like Simon says just because it's new it doesn't mean good

Last week I changed the battery in my hearing aid. Four hours later the aid was buzzing to say knackered battery. Put another in from the same pack and it's now fine.

[Turbocharger]

OK, making progress now.

Problem 1: fuel leaking back

I've changed the injector spill rail and the pipe that runs from the filter head to the injector pump

I've cracked the bleed screw on top of the filter while the engine's running, there's a healthy spurt of diesel so the lift pump's working well.

But it's still cranking for a while before it fires, and misfires for a few moments from cold. Next point of call is the glowplugs, though it still feels like diesel isn't present at the injectors initially.

Problem 2: poor cranking

Starter was changed two weeks ago and is known good from a mate's car.

Battery was replaced under warranty since it was at 80% of 'new' CCA

Earth leads have been cleaned and another earth run directly from battery to starter body

Pos lead has been cleaned at the battery end

Result: cranking is now acceptable (though it's excessively long because of problem 1).

This morning showed 10.5v across the new battery (right) and >9.5v across the starter (left) while cranking, drop is 0.3v on the negative side (bottom) and so maths says there's 0.5v on the pos side, which seems reasonably low for 350A.

Of course, now I don't know whether it was the battery or one of the leads - I should have looked at all the voltage drops earlier in the week when it was behaving strangely so I could see where volts were going missing, but hopefully the electrical problem is now resolved.

[Turbocharger]

Starting remains an issue - I'm now looking at the fuel system so I'll get the injectors away for reconditioning. Since December I have:

1: checked the compression on the car - all cylinders showing 320psi +/- 10%, so I don't see a problem there.

2: the heater plugs are all working individually, and I've rigged a wire to spark them up.

3: 15 secs of heater plug makes it start more quickly (though still some cranking required), but there's a substantial cloud of white smoke on startup (think "military tank smokescreen" density) and it's misfiring very badly for the first 30 secs of running. If I drop it to idle immediately while it's running on 2 cyls it'll stall - and then needs more cranking before it fires.

I'm thinking that the cold-start advance isn't functioning - easiest swap is the injectors (though it seems odd that they're all u/s at the same time), then I'll check the pump timing, then consider swapping the pump but by that point we're into bigger money.

Anything I've likely missed before I head down this route?

In better news - the electrical starting issue has been resolved. The battery was knackered and the earthing was poor, both now rectified.

[mmgemini]

That white smoke to me is unburnt fuel.

I was told by my injection guys that the injectors couldn't be srerviced. Only replaced. Is that the right information ?

I still think it the heater plugs. The plug timer relay I'm told keeps the plugs hot for 30seconds after starting.

How did you check the heater plugs ? There is only one way. Plugs out and a wire to one end and the other end to the battery.

HTH

[Turbocharger]

Yep Mike - checked them all individually while they were out to do the compression test, all glowed red hot within 5 secs of seeing 12v. I'm using a flylead to give them power manually but even after 30 secs of heat before cranking it's coughing, misfiring and chucking out white smoke for another minute or so before it settles down.

[steve b]

It sounds to me as if you have low compression , so a compression test would be in order . Blowing really hot air into the cold inlet

manifold will probably allow it to start instantly from cold , working heater plugs won't help low comp.

hth

cheers

Steveb

[mmgemini]

Have you checkd, I can't remember if you said so, the FIP timing. If the FIP is right, then how about the valve timing ?

[ejparrott]

Starting remains an issue - I'm now looking at the fuel system so I'll get the injectors away for reconditioning. Since December I have:

1: checked the compression on the car - all cylinders showing 320psi +/- 10%, so I don't see a problem there.

It sounds to me as if you have low compression , so a compression test would be in order .

[steve b]

oops missed that bit ...

was the comp test done warm or cold ?

Steveb

[TheRecklessEngineer]

My bet is still some sort of fuel issue. It doesn't take much of a hole to allow air in and diesel to flow back to the tank (or indeed forward down the return line).

Splice in a section of clear hose at the IP return to tank. When starting watch it - if you're getting air bubbles down the line then they'll be instantly visible.

[mmgemini]

My bet is still some sort of fuel issue. It doesn't take much of a hole to allow air in and diesel to flow back to the tank (or indeed forward down the return line).

Splice in a section of clear hose at the IP return to tank. When starting watch it - if you're getting air bubbles down the line then they'll be instantly visible.

If that was the case, why is the exhaust pumping out unburnt fuel ?

[TheRecklessEngineer]

Because with air in the injection pump, air gets into the lines to the injector. As air is compressible it has the effect of retarding the timing.

Normally, as the pump plunger pushes the diesel down the injector line, the fuel is compressed in a wave that passes down the line and to the injector. Pressure comes up, injector opens and squirts. If there's air in it, the air will compress absorbing the movement of the plunger and keeping the pressure low. Eventually, when the pressure comes up sufficiently the injector will open - but this is later in the cycle than usual giving symptoms of retarded timing (poor starting, white smoke etc etc).

[mmgemini]

How does it pull after it eventually starts

Smooth on powerful or holding back, especially on a bank ?

[Turbocharger]

Once it's running and the misfiring clears (takes 30 secs or so) it pulls as well as it ever has, though I generally don't thrash a cold engine.

I'm going to swap the injectors for some spares I have, and see if that makes a difference at all.

[mmgemini]

Have you changed the lift pump. They have a habit of letting the fuel run back to the tank, causing bad starting.

[Deej]

I'm interested to see how this turns out as I'm having the exact same issue - clouds of white smoke and misfiring for the first 30 secs or so and a slight but noticeable lack of pull. It's been particularly bad with the recent cold weather.

[TheRecklessEngineer]

My bet is still some sort of fuel issue. It doesn't take much of a hole to allow air in and diesel to flow back to the tank (or indeed forward down the return line).

Splice in a section of clear hose at the IP return to tank. When starting watch it - if you're getting air bubbles down the line then they'll be instantly visible.

I really do very strongly suspect you have an air leak. It could be a pump seal - say the front spindle shaft? Or even the throttle shaft. Or just a copper washer not sealing properly against the pump body.

If you splice in a length of clear hose (10 mins and a few pence for the jubilee clips and hose) you can instantly confirm/eliminate the fuel system rather than spending £100s on new injectors.

[Turbocharger]

Making progress but not out of the woods yet.

I changed the front two injectors for a couple of spares I have - no difference - so swapped out the rear pair. It now starts on the first turn, though it's still misfiring a little when it's cold.

[Turbocharger]

Hurrah! After lots of head scratching and wonderings about the combination of symptoms I decided to check pump timing... but the pin wouldn't go in. Eventually I got the pin to fit after I'd retarded the crank by about 11 degrees! I slackened the three books on the pump pulley and moved it to approximately the right place - much better.

It seems I'd forgotten how much faster it used to be as it degraded slowly over several years. Only recently it became obvious that it was dropping down to second gear on hills, even though the exhaust temps were as high or higher then ever. It steps of from standstill with much more vigour now, and I'm hoping I'll see more than 20 mpg too!

[Deej]

As I mentioned previously, I've been exploring a similar problem and thought there was no point starting a new thread.

I get grey/white smoke for the first 30 seconds or so after startup, which gets much, much worse between about 1500-2000rpm. There is a definite smell of unburnt fuel and I'm confident it's not steam. Engine doesn't loose any coolant or oil, no cross contamination of either etc. The problem is worse the colder it is.

Until a little bit of heat gets into the engine it feels slightly underpowered and does not rev as smoothly (sounds like it's knocking/missing a bit)

The timing is spot on, the glowplugs all work, valve clearances are correct, turbo doesn't feel loose, no oil in the inlet. So basically I've tried everything I can think of that doesn't cost money, and the next thing on the list is having the injectors tested.

Before removing the injectors I did a quick test by disconnecting them one at a time to see how it affected the smoke situation. Surprisingly the white smoke virtually disappeared when any one of the injectors was disconnected. When put back to normal the smoke returned.

Can anyone offer an explanation?

[Deej]

I've added a photo of one of the injectors. Does it look Ok?

[Josh NZ]

Sounds as if the said removed injector may be having problems with the spray pattern. It probably wants replacing

[Turbocharger]

Just to close this out I stripped off the timing belt and found that the crank nose bolt must have been slightly looser than spec, allowing the pulley to chatter. The wear pattern on the pulley suggest that it had been moving slightly - not enough to wear the crank but the woodruff key had milled a perfect slot into the pulley (which explains why it took a bit of swearing before I worked out how to slide it off)!

I replaced the pulley and the key itself, though the crank and keyway were undamaged. Now it's back together it's running much more happily and starts on the first turn.

[Deej]

That's really weird, it's as if the pulley was made from soft plastic. Would never have thought the woodruff key could cut into the (steel?) pulley that neatly.

[Deej]

Sounds as if the said removed injector may be having problems with the spray pattern. It probably wants replacing

The thing that I found confusing was that the smoke almost disappeared if any one of the injectors were disconnected. I was expecting it to stop when the duff one was disconnected, but they all seemed to have the same effect. The one in the picture I pulled out afterwards just to take a look, didn't have time to remove them all.