Hi all

Re the tittle what happens at 1800 to 2100 ish revs on start up? I am still having this cold start problem and its getting to the point now where im running out of things to try / replace

When i start from a cold start the revs drop and rise, if i rev the truck to say 1100 / 1300 it seems to clear its self but if i keep creeping the revs up as soon as i hit 1800 it starts to rev like crap again until the revs go past 2100ish then it seems to clear its self again and rev normaly. It only does this on cold starts when the trucks run and warm its perfect.

Question is does something open or shut at these revs?

Injectors tested all perfect
Brand new glow plugs + air seals
Brand new battery
EGR valve checked and great
Its not long had a service where air filter and fuel filter were changed
Computer didnt show any faults worth while

Any thoughts?

Dan Freelander 57 plate XS Blue Auto

Throttle body? There are more and more threads appearing where the throttle body appears to be failing in some form or another.

Some strip their teeth, others seem to fail for no reason. I took mine apart and the teeth were fine, but it just didn't work. Fitted a new one, and all my issues went away.

Thanks for the comment

Throttle body is something I will look into but I don't see how it would course this problem only at cold start? The general running of the truck ( revs ) seem faultless once warm, stops and starts perfectly, ticks over perfectly, revs perfectly

Maybe it could be the high lift pump, which would in turn mean a brand new high pressure pump as the lift pump is joined as one unit?

I have also checked all wiring plugs are in and cleaned the MAF sensor but made no difference

The search goes on lol

Cheers Freelander 57 plate XS Blue Auto

Odd that it is only from cold. I mentioned throttle body cause mine seemed physically ok,, but just didn't work properly (possibly bad position sensor in it). I get the feeling that it does quite a lot of work and feathers the in coming air to balance against egr recycling air and what not . . . I.e it's not necessarily responding solely to throttle pedal position ( could be wrong though on that ).

When you say cold start, do you just mean after its stood for a while or when it's particularly cold weather wise?

Could be a little bit of drain back of fuel whilst standing still, and that after the engine has run, it's drawn all the fuel back up no problems.

What's happens if you just start it and leave it at idle for a while. Does the hunting of the revs eventually settle as it begins to warm up?

Thanks again for the comment

That's the head scratcher as it only does it once the engine is cold ( in the blue on the temp gauge ) ( or its been left over night or all day ) Go out to it in the morning, get in start and it idles rough some smoke sometimes, and it just sits there idling between 800 and droping down to 600 and it jumps between then two, If you rev the engine up slowly it stutters until it gets over say 1000/1100rpm then it runs smooth and clear until the revs creep upto 1800 where it coughs and stutters its way through until 2000/2100 rpm where it then clears and revs smooth again, if you let off the throttle the revs drop back down and it will idle bad again.

If I get in the truck as above ( cold ), but revs the crap out of it ( boot the throttle and give it some hard high rpm for a lengh of time normaly puffs out some smoke ) then if you let the revs drop it will then idle perfectly.

If I get in the truck as above but just start it ( cold ) and drive off with out revving at a stand still she will drop the rpm to about 600 then drive off but clunk abit until I go around the block then it will idle fine.

If I go out and drive the truck, park somewhere ( shops ) then return to the truck where the engine temp gauge is above the blue ( cold ) and start it up it will idle perfect and rev perfect at a stand still ( also drive perfect )

The general driving of the truck seems get, pulls well dosnt cough if you stamp on the throttle, idles great when warm / hot. Starts everytime on the button hot or cold ( though this is my first winter with the truck so will see about the cold )

Like you say maybe its fuel draining back away from the lift pump, but then if so why would it stutter at 1800rpm through to 2100rpm every single time when the motor is cold? Could it be that the turbo spins up at 1800rpm and the ECM is trying to pump more fuel in to match the turbo air flow, and this is making the lift pump suck harder and not fueling propley until its pressured again?

As for starting it and just letting it idle for sometime I have not done this yet but I will try so in abit to see what happens, the most time I have let it idle for is maybe 20 seconds

I took the glow plug relay out yesterday before starting the truck in the morning and it seemed to idle worse with the revs jumping about more harshly than its normal bad idling

Cheers again Freelander 57 plate XS Blue Auto

Interesting. My initial thoughts are that there is some issue with temperature related fuelling.

When you say it puffs out smoke, what color? Black or white.

Variable vanes on the turbo stiff/sticking maybe

That thought had crossed my mind as well, but if i recall from experience of my turbo vane controller going kaput, it showed an engine management light right from the outset of turning on the ignition and completing its system checks at start up. Variable vane position being wrong I don't see making a difference to the engine enough that it would stutter as bad as being described here. Sure, it might mean it could dip its airflow and affect power or turbo spool up, but to make the engine cough, I would be surprised ( could be wrong though )

Off shore ... do you fancy trying one obscure test for me? Next cold start from the house, how about taking a hair dryer out to the engine bay, and sticking it onto the throttle body for a good while so that it heats the throttle body up and gets nice and toasty warm, then starting it.

As I say, a bit random, but hey ! costs nothing but some time !

I'd also say it may be worth investing in some form of OBD2 stuff to start seeing the data that the engine is working from.

Fisha today I started the truck on tick over only and let it idle until upto full running temp with no throttle input at all

Started with its normal idle problem, as soon as the engine warmed up above the blue temp gauge it then started to idle fine, after awhile when it warmed up to normal running temp I then revved it up to 3000 or so rpm and it revved perfect with no smoke ( revved freely ) When the revs dropped back down it idled fine again. So this problem only seems to happen on a dead cold engine ( the air temp today was 17oc )

I did have ago at filming this but tbh it looks naff and didn't really get what I was trying to

I can give it ago with the hair dryer next week to see if that makes a difference The throttle body its self seems to be working fine as it does the start up and shut down with out problems ( you can hear it open and close fine or close and open )

I will make another vid of the start and throttle when cold to show the difference



Cheers

Dan Freelander 57 plate XS Blue Auto

Did you put the injectors back in the same places? Inj1 to Cyl1, 2-2, 3-3, 4-4?

Injectors tested OK statically or dynamically?
By static I mean a simple volume/second measuring with a constant pressure in the rail and a fixed impulse drive. By dynamic I mean various pressures in the rail and various impulses length.

Also see that on the injectors' return line (leak off pipe) there is a 10 bar non-return valve.
Check it as it's important for proper functioning of these injectors as it maintains a constant pressure in the injectors' hydraulic chamber.

""Did you put the injectors back in the same places? Inj1 to Cyl1, 2-2, 3-3, 4-4?

Injectors tested OK statically or dynamically?
By static I mean a simple volume/second measuring with a constant pressure in the rail and a fixed impulse drive. By dynamic I mean various pressures in the rail and various impulses length.

Also see that on the injectors' return line (leak off pipe) there is a 10 bar non-return valve.
Check it as it's important for proper functioning of these injectors as it maintains a constant pressure in the injectors' hydraulic chamber.""

They were removed and numbered and taken to a local injector shop, and had full testing and were reconditioned, all are working as perfect No tests have been carried out while they were fitted other than kieth gotts plugged in there computer and they said all was looking fine ( though the drive up to Gotts from mine is 40 miles so it was at full running temp when they plugged in to the truck ) They never tested anything when the truck was cold.

Its funny you mentioned the injector leak off pipe as we didn't know it held back that much pressure, will be driving the truck later and then once home un clipping the quick release for the valve and seeing if over night any fuel drips out, I think this would show if its leaking? Not sure how else to test it as we don't have any tools to test it?

It seems the leak off pipe is under £50 so will order another one from landrover sometime next week

Thanks for the advice as it might of steered us in the right direction

Dan Freelander 57 plate XS Blue Auto

Todays update

No rain today at last lol

Went out started truck ( normal problems still there ), bonnet open, took engine cover off, stood there for 5 minutes while it was warming up with intent to unplug the injector leak off pipe valve ( once it was warm and engine turned off ) Before I got to this point I was looking around at the filter and noticed a rather large bubble come out the filter and pass through the fuel line to the high lift pump! and moving the sheaf up the pipe to see the clear fuel line, all I could see was fuel and ( tiny bubbles and then every now and then a few large ones go through the pipe )

I have turned the truck off and will wait till this evening to see if the line runs dry or if it still has fuel inside once the engine is cold, seems this is ment to be a air tight fuel system I guess this is the problem that im having?

I do have a brand new Mann fuel filter that I got the other day. Im guess either the filter is sucking in air, or a connector is not fitting tight or a split in the fuel line, tank side of the filter ( though no diesel has ever leaked to the ground from the truck )

As the truck was idling for around 10 minutes and being revved upto 3000 rpm by myself it was still sucking bubbles from the filter to the lift pump so I guess its air getting in all the time?

Dan Freelander 57 plate XS Blue Auto

Well that certainly needs addressing. As you say it reads as though you are drawing in air.

In fact I'm sure I read about the fuel filter having a setup which directs flow through the top section of the filter depending on the temperature of the engine which may explain the cold warm difference in preformance.

New filters need primed properly. I have a bulb thing which I connect after the filter and use to draw fuel through the filter and into a jar and I keep drawing till the fluid runs clear of bubbles.

I think in your case I would disconnect the 4 pipes to the filter and give the connectors a good wipe clean and then re prime and try again. The bulb thing is easy to buy and was about 20 quid.

Bubbles on mine too, especially when the RPM drops from the high range, but no problems.
A few bubbles now an then it's no problem, I believe, as the common rail volume is quite big and the injected quantity is very low during operation. If it were a real issue, the start would be problematic.

Hi guys thanks for the replys again

I waited and let it cool down again to cold and restarted and loads of air come out the filter through the pipe to the high lift pump and the truck stuttered and coughed as normal, watching the fuel lines that return to the filter they turned milky in colour im guessing because of the bubbles being blasted by the pumps and pushed back down the return pipes... once the engine cleared itself after a few minutes the fuel return lines went back to normal diesel clear colour

A air leak seems to be the problem from what i have seen today so just got to find the problem area now. The search goes on lol

Cheers again Freelander 57 plate XS Blue Auto