td4 starting prob

Hi to all need some advice please, have a td4 on 04 that sometimes has a problem starting when left all day or overnight, eventually catches with a puff off diesel. Now it's done 91K and well serviced, had a new pre pump 10k ago - pvc 20k - fuel filter -turbo vent - egr bypass - k&n air filter 5k ago synergie 2 set to 4 but later set to 3 for better economy 3.5k oil and filter + sediment drain every 3K. Runs fine with some clatter when cold (worse on setting 4 but assume this is normal) checked all terminals for corrosion and found none anywhere. Starts fine when hot so assume crank sensor fine, pre pump runs for 1 min dead with no leaks or damaged pipes that I can see.Have been using Tesco fuel???? not sure if that makes a difference and have disconnected the high pressure harness on the synergie but left the mafam for now.NOW FOR THE QUESTION: Did a leak back test with ignition ON and pre pump only not cranking and nothing came out of the top of the injectors at all after around 40 seconds (IS THIS CORRECT), there was fuel in the return pipe when removed. Sometimes when I pull up and park it smells a bit rich maybee! Not let me down yet but want to catch it before it does. Are there any other things I should test for? mechanical or electrical?

cam sensor?

Thanks will look into cam sensor theory, but would still like to know if diesel always come out on a leak off test?

The cam sensor would be worse with a warm engine.
Check that the contacts on the high pressure fuel sensor are clean both on the plug and socket, this is a common cause of bad starting.
There should be a thread on leak back testing just have a quick search but as far as I know if nothing comes out after 10 secs thats ok, although the only way to be certain is to test them whilst cranking the engine as they have been known to pass the ignition test only to fail when cranking under high pressure,..... replacement pumps have been known to go very quickly if they are a pattern unit.......oh and whats a pvc? (although i may be being thick)

Did wonder about that in comparison to most threads! PVC was what the dealer put down for the crankcase breather (might be a type error). Yes checked all connectors especially as I had the synergie on and off the rail switch. So from all the threads I can find they all state that they shouldn't leak to early but nobody mentions what should happen if you go for the full minute, tempted to put a pressure gauge on as I understand it's around 30-35psi but thought I would ask first as it's in daily use. Under cranking I assume the injectors are designed to act as a return above the operating pressure so assume they will pump fuel and it needs to be measured to ensure all injectors are working evenly? If someone can confirm the aforementioned test results I would be very grateful.

Crankcase breather should be replaced at every service without fail! so its 10k overdue, you can upgrade this to a bmw cyclonic unit that costs approx £24 and just needs cleaning out now and then. If this gets blocked it causes no end of problems so before i tried anything else i'd get this changed asap.

Thanks will sort asap, any ideas on the leak test

You can by a kit for doing the leak back test, it involves a set of pipes and collection pots....if you look on e-bay you'll find them readily available.......not done one myself but i'msure others on here would be able to give advise if you get stuck.

have you check to see if your glow plugs are working?

Too warm over here in Blighty for them to kick at the moment, as far as i know they only need to glow at below 5 degrees on the td4

mjrimmer said:

Too warm over here in Blighty for them to kick at the moment, as far as i know they only need to glow at below 5 degrees on the td4

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they come on when you turn on the key at the same time your fuel system primes itself.It make it easier starting and easier on the engine and starter

mjrimmer said:

Too warm over here in Blighty for them to kick at the moment, as far as i know they only need to glow at below 5 degrees on the td4

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Wrong looked up glow plugs for land rover and they work in all temperatures . There is a mirco processor under the bonnet that measures the ambient temperature on the motor and that is what sends the electric to the glow plugs and they are timed for 30seconds to 180 seconds before start lite comes on.They don't work on a warm motor. Out side air temp has no effect of glow plugs working.

It takes approximately 1850 degrees F for diesel for combustion in the cylinder

I can't be arsed arguing but...........nah! can't be arsed.

MJ got the breather off today and would probably say it hadn't done 20k so must have missed that when looking through the history. Regardless to say have fitted the BMW dyson looking item (12 7 799 367) "if you haven't fitted one this number this will be useful". Have studied the threads on cranking leak off test but couldn't see a suggest time. Anyone now how long to crank or is it just until you have a good comparison across the injectors?

As far as i know you use collector pots for each injector so i assume you'd want to stop before any of them is full

mjrimmer said:

As far as i know you use collector pots for each injector so i assume you'd want to stop before any of them is full

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Ok in reference to the first post. Go to 13 October 2005 0905 name is DENNISS had the same problem you have . Please read this as it could save you some money.. Just tryin to help and you don't seem to want the help.

Hi John it would be easier if you copy and paste the link in your post it saves any noobs doing a search + At the moment i don't need any help..... many thanks any way mines running like a dream and if at any time it aint .....I fix it

Hi, all replies are welcome and I did see the denniss thread along with several hundred others before deciding start this one, so looking to do leak off test at while cranking this weekend just for peace of mind as it not expensive. From experience does the maf - mafam sensor have any affect on starting? does anyone have any issues using Tesco diesel?

Apologies for this short intermission while ebay delivers my test kit. "If time is money did I really save some or spend more".

So thought I would check the glow plugs while I waited and YES one was open circuit, but then number one plug sheered off and to cap it all the stud extractor snapped off inside that, so as I was usc without a paddle I bit the bullet and got some carbide drills and more luck than judgement managed to get it out and save enough thread for one to go back in "yes there is a god" So a day of drilling and half a day degreasing the inlet manifold I would say it is running quite sweet. However I finally run a test with the running leak back test and got the following results "in the collection bottles"
70 - 80 - 72.5 - 82
So does this mean 80 and 82 are loosing pressure or 70 and 72.5 injecting to much? the difference between the highest and lowest is around 17% so which way do I go or is that normal?