406 1.9 td poor start

rayc · Post by **rayc** » 21 May 2008, 21:28

My sons S plate 406 is suffering starting problems in the morning.

Glow plug relay light stays on for anything between 5 & 10 seconds.

Glow plugs replaced and are fine

Leak off pipes replaced.

Symptoms are it starts on a lumpy "3" and then after 15 seconds it runs fine.
After the morning cold start it runs fine during the day but it needs partial throttle like a petrol car to start.

It's got the bosch injection and I cant see any leaks!

Any advise would be appreciated

Thanks

Ray

AndersDK · Post by **AndersDK** » 22 May 2008, 17:27

No matter you cant see any leaks - they are there. Especially on the feed side of the pump.

The last bit of fuel hose from fuel filter to pump MUST be replaced with a clear/opaque hose (PVC) to recognise an air problem in the fuel - which by far is the most common problem causing the symptom you describe.

Even the smalliest few air bubbles are NO-NO's in a diesel

Its NOTHING like a petrol

Post by **RichardW** » 23 May 2008, 07:46

Try pumping the primer before starting, this should help the starting if it is air leak problem. If this doesn't help, then consider digging out the feeler gauges and checking the valve clearances.

greg123 · Post by **greg123** » 22 Jun 2008, 23:30

If priming doesn't work, check the valve clearances and injection timing - both can cause it, especially if the timing is slightly retarded.

If not that and your compression is good, take a look at the nozzles, over 80k and original worth getting them replaced and injectors pop tested anyhow.

Greg.

rayc · Post by **rayc** » 14 Dec 2008, 15:52

Me again!

Son's now moved on to a 2ltr 406 coupe and has left me with the 406 diesel.

Since this post started. His cam belt snapped after the fan belt came off (Luckily whilst starting). It snapped the camshaft so I bought a replacement s/h head. Had it checked and fitted.

Still a bitch to start when cold. Changed glow plugs but they are ngk and I'm wondering if they are not up to the job (correct 11v jobbies).

When cranking from cold it actually sounds as though the car is lacking compression. She'll start to kick on one then two then 3 then three and a half and start. She's fine all day then.
Fuel leak back / air was due to the hose clip on top of the filter. Now done and the fuel bulb is hard all the time so pressure is good.

Valve clearances? Is it a big job? Belt off etc. If so I'll have to get someone to do it? Is it worth me changing the glow plugs to Beru ones?

The old girl has just flown through it's mot but I need to sort as the old financial credit crunch is starting to hit and I need to get some money coming in (No work as er many at the mom). I wont sell it until I rectify the problem as it isn't the done thing.
Car drives like an absolute dream apart from first start of the day.

It's a bosch pump. EGR blanked (Only as pipe was broken on valve) but runs great. Oh and one slightly noisy tappet (possibly loose but no issues when driving)
Cheers everyone

Thanks

greg123 · Post by **greg123** » 14 Dec 2008, 17:58

Hi,

So you put a 2nd hand head on but didn't have the valves ground in & tappets set while it was off? This could be your compression issue/rattle.

However, to really clarify where you are at and eliminate stabbing in the dark, have a compression check from cold. You can do this via the glow plug holes. Once you establish if you have good compression and even compression on all cylinders, post back. It should be 25-30 bar. Your valve clearances should be 0.15mm inlet 0.30mm exhaust. You can check them without removing the cam/cambelt. Slightly wide clearances you can live with, tighter than spec should be rectified as that can cause compression loss and burning out of valves.

My advice is not to get into the label on the packet of the glow plugs issue. NGK are a massive company, OEM suppliers and one of the world leaders in plugs & glowplugs. In any case, so long as they all have continuity & are the correct ones, they will look and act the same as any other. Some people have used alternatives, mainly longer ones, but these can also project further into the spray pattern and make for worse running/fuel mixing and as an extreme burnt out glow plugs.

On the basis that I ran one of these engines for 4 years with bog standard pattern glow plugs on a single tank vegoil conversion, starting at sub zero temps on 80% oil first time on all 4 cylinders, I think chasing glow plugs is avoiding the real problem. The compression, valve clearances were perfect on the motor though, I advanced ignition timig slightly and the injectors I had rebuilt. It ran well.

Blanking the EGR is a good thing to do, leave it like that.

Greg.

rayc wrote:Me again!

Son's now moved on to a 2ltr 406 coupe and has left me with the 406 diesel.

Since this post started. His cam belt snapped after the fan belt came off (Luckily whilst starting). It snapped the camshaft so I bought a replacement s/h head. Had it checked and fitted.

Still a bitch to start when cold. Changed glow plugs but they are ngk and I'm wondering if they are not up to the job (correct 11v jobbies).

When cranking from cold it actually sounds as though the car is lacking compression. She'll start to kick on one then two then 3 then three and a half and start. She's fine all day then.
Fuel leak back / air was due to the hose clip on top of the filter. Now done and the fuel bulb is hard all the time so pressure is good.

Valve clearances? Is it a big job? Belt off etc. If so I'll have to get someone to do it? Is it worth me changing the glow plugs to Beru ones?

The old girl has just flown through it's mot but I need to sort as the old financial credit crunch is starting to hit and I need to get some money coming in (No work as er many at the mom). I wont sell it until I rectify the problem as it isn't the done thing.
Car drives like an absolute dream apart from first start of the day.

It's a bosch pump. EGR blanked (Only as pipe was broken on valve) but runs great. Oh and one slightly noisy tappet (possibly loose but no issues when driving)
Cheers everyone

Thanks

rayc · Post by **rayc** » 14 Dec 2008, 18:11

Hi Greg,

I had the head was skimmed, Valves done and one of the pre combustion chambers sorted (it was slightly loose) so from that side all is ok.

I'll have a dabble at the valves clearances and will see if I can get the compressions done.

As for the glow plugs. I know some brands do suffer (Although I agree NGK are a good make) due to their tolerances being different.

I cant understand these issues really as the starting happened after the glow plugs were changed and have continued now the head has been changed. I was wondering if maybe the glow plugs have heat ranges and maybe these are too low. I had all the injectors refurbed approx 8,000 miles ago and the sensor on no. 3 is working as it should.

So, gaps and compression next on the agenda. Thanks for the advice

Ray

greg123 · Post by **greg123** » 14 Dec 2008, 22:38

Hi Ray,

Any engineering shop who seated the valves should have set the clearances at the same time. Otherwise upon fitting the cam some may not even close! But check them anyhow - likewise good to know the compression. If worried about the glow plugs you can always put a fresh set in and check the voltage, lower than 11v and I'd be looking at the supply (jump a heavy duty cable from battery +ve) rather than the plugs.

Good luck and let me know how it goes,
Greg.

rayc wrote:Hi Greg,

I had the head was skimmed, Valves done and one of the pre combustion chambers sorted (it was slightly loose) so from that side all is ok.

I'll have a dabble at the valves clearances and will see if I can get the compressions done.

As for the glow plugs. I know some brands do suffer (Although I agree NGK are a good make) due to their tolerances being different.

I cant understand these issues really as the starting happened after the glow plugs were changed and have continued now the head has been changed. I was wondering if maybe the glow plugs have heat ranges and maybe these are too low. I had all the injectors refurbed approx 8,000 miles ago and the sensor on no. 3 is working as it should.

So, gaps and compression next on the agenda. Thanks for the advice

Ray

rayc · Post by **rayc** » 14 Dec 2008, 22:56

Hi Greg,
I'll double check the clearances anyway in case they've "settled".

I checked the voltage earlier and the relay is putting 11 volts to all points of the plug tops.

When I started it tonight it hiccuped after starting just like a dodgy glowplug would cause. So I'll whip them out I reckon.

What should the resistance be on them?

I'll keep you updated.

Ray

AndersDK · Post by **AndersDK** » 14 Dec 2008, 23:35

ohmic resistance on a cold glowplug is approx 0.8-1 ohm, which in normal terms equals a shortcircuit.
If you go try them out using a car battery : beware of the heat. They will (should) be glowing WHITE hot.

theasylum · Post by **theasylum** » 15 Dec 2008, 16:51

i had the exact same problem with my 806 tdi. first thing in the morning i would wait for the glow plug light to go out then try and turn it over but it sounds like ist only running on two cylinders after aprox 6 sec of peddle tapping would it come to life on all 4. bellowing smoke out the back. ive been having electrical problems and changed the battery allthough it tested fine and the problem cured itself. can only asume the diesel was thicker in this cold weather and it needed a little more umph.

rayc · Post by **rayc** » 15 Dec 2008, 18:58

I've ordered some new glowplugs to be sure.

I'll be checking the valve clearances when it's cold and I have time.

I'm now thinking about the ECU temp sensor. If that is faulty and thinking the engine is warm would it reduce the time allowed to the glow plugs for heat? or am I just being wishful!

Post by **CitroJim** » 15 Dec 2008, 20:31

rayc wrote:I've ordered some new glowplugs to be sure.

I'll be checking the valve clearances when it's cold and I have time.

I'm now thinking about the ECU temp sensor. If that is faulty and thinking the engine is warm would it reduce the time allowed to the glow plugs for heat? or am I just being wishful!

Not a bad itea Ray. I fell ito a trap with my 2.1TD. I was supplied non-turbo Glowplugs (BERU GV636) whereas the corrct ones are BERU GN909. The GV636 ones take longer to heat, don't get as hot and cannot tolerate post-heating so do make sure you get the right ones. Generally, Non-turbo engines need far less preheating than a turbo. It really does make a difference to have the right glowplugs. I current run a set of NGKs and they seem OK.

Good idea to check the CTS as when cold the glowplugs post-heat (i.e stay glowing) for up to 3 minutes after starting and this is controlled directly by the engine ECU.

rayc · Post by **rayc** » 15 Dec 2008, 20:52

Cheers Jim,

That's what I'm hoping.

If it's wrong plugs I'm sorted. I'll keep you all updated!

rayc · Post by **rayc** » 16 Dec 2008, 17:14

Well!

Bought glowplugs from an Ebay seller yesterday and they arrived this morning!

I asked specifically if they were the long glow which he confirmed they were.

I set of glowplugs fitted. Car started IMMEDIATELY from Cold and so far today has been on the button and it's 2 degree's!

Fingers crossed that it's the same tomorrow!

Moral of the story. Dont assume the plugs are the right ones. Bosch were in the car and can only assume they've gone weak or were the wrong ones!
No diesel knock, no hesitation. All I need to hope is the plugs last (They have a 12 month unlimited mileage warranty so they advertise) at the grand sum of £18.50 delivered!

I'll let you know if my good fortune lasts!