TD4 Hot start

[psproule]

So our newly acquired 2001 TD4 is afflicted with the intermittent hot start problem. Most of the time it is fine - goes like a little rocket (relative for a diesel) with no misfires or silliness, but occasionally it will refuse to restart after a run. It will crank, and maybe fire one cylinder but then not start. Leave it for a few hours and it will start. Of course it does it at the most inopportune times

Reading around the forums it seems that quite a few things can contribute to this: Cam angle sensor, crank angle sensor, lift pump, secondary pump, leaky injectors and possibly an AFM or dry solder joint in the ECU. Any suggestions from those more seasoned on which one to start with? I guess when I next get it to fault I can have a look if fuel is being delivered and for injector leaks. It does seem to correlate with being parked on a slight front to rear incline so perhaps it is a pump. You can hear the front one running. Who's idea was it for these to have 3 pumps anyway?

I should have an OBD computer interface here soon that might shed some clues from the ECU.

Regards - Pat

[woko]

Sounds like Cam or crank angle sensor. more likely Cam sensor. It will log a fault, so get the codes checked. Don't open any injector lines when running or cranking they are under extremely high pressure and is dangerous

[psproule]

Thanks Woko. I have a friend who runs a Bosch diesel service centre (Denco Diesel) so if it gets to playing with Injectors I'll go see him. And thanks for the info re it logging a code - I wasn't sure if it would so that will be a good place to start.

Are parts from Land Rover reasonable? Unfortunately there is no local dealer. I have noticed a lot of spares available from Land Rover specialists and the like, particularly through EBay UK.

Pat

[Jojo]

Check camshaft sensor (easy to replace), but my bet is on the fuel pump in the right hand side rear wheel arch. Replacement is a bit fiddly, and you have to dissemble half the car, but usually this will cure the problem. Been there, done that (unfortunately first after replacing all the sensors, one after one, because I was too lazy and frugal to fork out the money for the pump and get the job done. It didn't let me off though...).
Cheers

[psproule]

Still waiting on a cam sensor and OBDII interface to be delivered, and it has played up a bit. So following a suggestion about the pump above we pulled the rear (in tank) fuel pump out and found it almost completely blocked with crud. See Pics attached.


We cleaned it out and it appears to be running fine. We ran it with the fuel line off and it appears to flow well. Later that day it got into the fault mode again so we popped the line off the pump to see if it had stopped, but it was still flowing very well. I'm still a little suspicious though as the ECU does take a reading of fuel pressure before the common rail pump and will refuse to start if there is not enough fuel supply. I'm guessing looking into computer codes is likely to give me the answer.

Interestingly the Melbourne based LR specialist I spoke to on the day argued with me that the TD4 did not have an in-tank pump. What year did they drop the second pump?

Pat

[BigJon]

When I used to work at a Dealer we had one of these displaying the same symptoms.

It got all the parts you have mentioned replaced in an effort to resolve the issue.

The final fix was to replace the entire vehicle wiring loom . As far as I am aware it did fix the problem.

[101RRS]

Interestingly the Melbourne based LR specialist I spoke to on the day argued with me that the TD4 did not have an in-tank pump. What year did they drop the second pump?

Pat

Interestingly I have Land Rover people often telling me my L series (not a TD4) has an intank lift pump but it is just not so.

My L series has a suction bulb in the fuel line - like on outboard fuel tanks - that sucks fuel up from the tank to the injection pump. On the TD4 there is a lift pump in the tank (as you have found) that provides fuel to the pump that pressurises the common rail.

So the change is when the Rover L series Diesel was replaced with the BMW TD4 Diesel - basically on the first face lift of the FL1 in 2000.

Garry

[woko]

TD4's have 3 pumps, 1 mechanical (high pressure) and 2 electric (low pressure).

[101RRS]

TD4's have 3 pumps, 1 mechanical (high pressure) and 2 electric (low pressure).

I assume the mechanical is the main injection pump and one of the electric is the tank lift pump - what is the other and what does it do?

[Jojo]

Well, here seems to be some confusion here. The early Td4 models apparently had a in-tank mounted lift pump, whereas the later models had one fitted in the reight hand side rear wheel arch. All of them have a high pressure pump as well.

Cheers