Must read for TDCi owners

[PAT303]

Just a bit more important info for owners,as we all know the TDCi is renowned for it's clunking drive train and originally all the blame fell on the P38 diff,since owning mine I've found the axle flanges and adapter shaft to be the bigger issue,I've now found another cause,the VCV.Our TDCi started with the hunting idle and stalling a few weeks ago which just happened to be when I noticed the drive line slack had returned,I've been doing a bit of Perth driving and it is crap to put it nicely,I could not drive it smooth.Well I've just returned from Perth with a new VCV fitted and guess what,never had a single clunk the whole way.I've always put up with the little hesitation off idle with my engine because that seemed to be a TDCi trait but it's not,it's that little cough that causes the loading/unloading of the drive train that then causes the cur-clunk every time you change gear.I'd strongly advise that if you find you cannot smoothing drive away from idle and you have a 2.4 I'd look at replacing the VCV,it is a known fault that will need to be replaced anyway so I'd do it now,the smoothness of my engine is chalk and cheese compared to two days ago. Pat

[roverrescue]

Pat,
I also noted an improvement in low speed throttle inputs once closing the EGR via BAS (no ECU remap just an EGR close).
During the pump learn process following remap my VCV took a few times to learn.
Dave suggested that is an early indicator for VCV failure.
I have pencilled in a pre-emptive strike on the VCV and after your good report might bump it up the list.

Did you source and install the part? I have seen them readily available from the UK for part (LR009837) however I would prefer a Denso or Genuine LR unit if Im going to do the swap?

S

[TimNZ]

I've also found front bump stop clearance to be a factor in drive line clunk. With and ARB bar and winch on the front of my 110 the bump clearance dropped to ~70mm. I fitted the LR HD springs which raised the clearance up to ~105mm. The car went from easy to drive, relatively clunk free, to an absolute pig.

After doing a bit of maths I settled on Les Richmond Automotive's "Rangie Pink" springs. These brought the clearance back to (stock) ~90mm and the car is back to it's old easy to drive self.

It amazes me how much this small 15mm lift made to the driveability, (I know that's not a word Ron! :) ).

Cheers,

[PAT303]

Pat,
I also noted an improvement in low speed throttle inputs once closing the EGR via BAS (no ECU remap just an EGR close).
During the pump learn process following remap my VCV took a few times to learn.
Dave suggested that is an early indicator for VCV failure.
I have pencilled in a pre-emptive strike on the VCV and after your good report might bump it up the list.

Did you source and install the part? I have seen them readily available from the UK for part (LR009837) however I would prefer a Denso or Genuine LR unit if Im going to do the swap?

S

I had the denso model fitted,I didn't do it as I don't have the software to do the pump learn,I also looked at getting the EGR closed via a remap. Pat

[YOLO110]

What/where is the VCV please guys? :confused:

[Grumbles]

What/where is the VCV please guys? :confused:

Volume Control Valve but am still not much wiser about it.:confused:

I didn't know either so I had to Google it - got a lot of hits talking about and endorsing what Pat posted.

[1nando]

Is this issue more likely in the 2.4s as opposed to the 2.2s or is it the same in both?

Sent from my SM-G925I using AULRO mobile app

[roverrescue]

Yolo
From the Manual VCV is part of the low pressure fuel system

The transfer pump draws fuel out of the fuel tank through the fuel inlet (8). The pump internal pressure is adjusted through the admission-pressure control valve (6), ensuring that sufficient lubrication and cooling are always provided for the high-pressure pump components. The excess fuel is transferred to the inlet side of the transfer pump (7) through the admission-pressure control valve, with a portion of the fuel being transferred to the VCV (5) from the transfer
pump. The fuel quantity delivered to the high-pressure chambers is determined by the opening cross-section of the VCV. The small restriction bore in the fuel overflow valve (14) provides for automatic bleeding of the high-pressure pump. The entire low-pressure system is designed to allow a defined quantity of fuel to flow back into the fuel tank through the overflow pressure regulator tube, which assists cooling of the high-pressure pump.
A total of 2 high-pressure chambers (1 and 2), each with a pump plunger (3), are used for high-pressure generation. The drive for the pump plungers is through an eccentric cam (11), which is in turn driven by the drive shaft (12). The high-pressure pump permanently generates the high system pressure for the fuel rail.

[DefenderSte]

Just a bit more important info for owners,as we all know the TDCi is renowned for it's clunking drive train and originally all the blame fell on the P38 diff,since owning mine I've found the axle flanges and adapter shaft to be the bigger issue,I've now found another cause,the VCV.Our TDCi started with the hunting idle and stalling a few weeks ago which just happened to be when I noticed the drive line slack had returned,I've been doing a bit of Perth driving and it is crap to put it nicely,I could not drive it smooth.Well I've just returned from Perth with a new VCV fitted and guess what,never had a single clunk the whole way.I've always put up with the little hesitation off idle with my engine because that seemed to be a TDCi trait but it's not,it's that little cough that causes the loading/unloading of the drive train that then causes the cur-clunk every time you change gear.I'd strongly advise that if you find you cannot smoothing drive away from idle and you have a 2.4 I'd look at replacing the VCV,it is a known fault that will need to be replaced anyway so I'd do it now,the smoothness of my engine is chalk and cheese compared to two days ago. Pat

Cheers Pat,

Having read your post thats my defender to a tee hunting then stalling and trying as i might for a smooth gear change its just not happening.

:D:D:D

[PAT303]

Is this issue more likely in the 2.4s as opposed to the 2.2s or is it the same in both?

Sent from my SM-G925I using AULRO mobile app

The last of the 2.4's as well as the VM powered Jeeps as both use the same Valve.The 2.2's don't seem to have the issue at all. Pat

[ozy013]

What/where is the VCV please guys? :confused:

Number 1 is the VCV
https://www.aulro.com/afvb/images/imported/2016/07/1078.jpg

[DefenderSte]

Thanks Ozy for the pic....:)



As i don't have the softwear even if it did get the part to fit myself......

So me thinks its off to the garage to get this problem rectified. I just hope that it won't cost a small fortune.....:D:D:D

[ozy013]

It shouldn't cost a fortune, (famous last words), as the pump learn takes all of a minute or so, and unlike other jobs, the valve is very easy to get to and replace.

[DefenderSte]

Looking at the pic Ozy is it on the left side of the engine as you look into the engine bay...??:D:D




Number 1 is the VCV
https://www.aulro.com/afvb/images/imported/2016/07/1078.jpg

[ATH]

Yes it's on the left and you need skinny hands and strangely bent hands and arms to get into it. Or use 3/8" drive socket with a long extension.
AlanH.

[DazzaTD5]

Just some info....
FCV, VCV, SCV.... metering unit etc etc...

*is nothing more than a single circuit fuel shut off solenoid.
*Used on all common rail diesel engines I've worked on.
*Bolts to the back of the High pressure fuel pump.
*Actually doesnt require "calibrating", simply requires the duty cycle to be reset.
*Most other engines, dont have a duty cycle reset requirement, simply replace unit and move on.
*Its one of the more common components I replace on both Jeep and Land Rover diesel models, I'm sure other brands are just as prone to failure as well.

the Denso (brand name) ones (used on Toyota, Nissan, Ford etc etc) seem more prone to sticking than the Bosch ones as used on Jeeps (and Mercs, Iveco etc etc).

Regards
Daz

[PAT303]

As I posted first up,I should have got you to replace mine earlier as it's totally changed the way it drives,have you got a reply as to the EGR shut off?. Pat

[DefenderSte]

Well I dropped mine at the garage yesterday and the mechanic plugged in the software and got back to me. He said that the computer is asking the fuel pump to chuck in more fuel but the pump aint doing that.

So he thinks it might be the pump but wanted to keep hold of it for further investigation...... so as they say no news is good news.....lol lol

Watch this space.....:D:D:D

[newhue]

It doesn't take much to upset them. I have always purchased diesel from flashy major brands. But mine hunted at idle for sometime, and would also do it at low speeds but never affected noticeable performance. Eventually it stopped one day, and then another but restarted first crank after the event. $700 for a VCV and a injector re learn and it idles and runs fine again now.
I now use Fuel Doctor in every tank. Have bought a water alarm for the standard stanadyne filter but haven't fitted it yet, and change the fuel filter with every 10K oil service. All a PITA but cheaper than the inconvenience of it not going.

[PAT303]

It doesn't take much to upset them. I have always purchased diesel from flashy major brands. But mine hunted at idle for sometime, and would also do it at low speeds but never affected noticeable performance. Eventually it stopped one day, and then another but restarted first crank after the event. $700 for a VCV and a injector re learn and it idles and runs fine again now.
I now use Fuel Doctor in every tank. Have bought a water alarm for the standard stanadyne filter but haven't fitted it yet, and change the fuel filter with every 10K oil service. All a PITA but cheaper than the inconvenience of it not going.

Thats more than twice what I paid to replace mine :o. Pat

[newhue]

Pat, I took it to SEQ premier aftermarket LR specialist. They supplied and fitted. Probably should have shopped around, but when it's your daily driver work vehicle a reliable fix is better than a cheap fix. Shame they are so fickle in the first place. Price of modern performance sadly.