*Fixed!* Hard to start Disco after major work

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Alpinejim

Active Member
Posts
238
Location
Sunny Suffolk
I have changed the TD5 engine in my D2 and I'm having a hell of a job getting it to start and run reliably.
I reconditioned the head and replaced all gaskets and O rings for the fuel lines around the head. I also changed the fuel filter at the same time and no, I didn't fill it with diesel before fitting it.

I ran the fuel priming proceedure a few times and tried to start and failed.
I ran it another 7 times and it started, but it only ran for a minute or so before cutting out.
Another 6 primes and another start before cutting out after a few minutes.

Today I am again priming a few times and starting but each time it will only run for a couple of minutes.

It would seem that there is air in there still but can it still be after so many purges and running? Or is it possible that something has failed during all of this work? The pump is noisey and may well be original on a 53 plate so I'm thinking that all of the purging has tipped it over the edge but, before I go spending money, can anyone suggest something that I may have overlooked?
 
Silly suggestion but I have seen it before....

You have deffo got the fuel lines connected back on the correct way, feed and return?









Alpinejim said:
I have changed the TD5 engine in my D2 and I'm having a hell of a job getting it to start and run reliably.
I reconditioned the head and replaced all gaskets and O rings for the fuel lines around the head. I also changed the fuel filter at the same time and no, I didn't fill it with diesel before fitting it.

I ran the fuel priming proceedure a few times and tried to start and failed.
I ran it another 7 times and it started, but it only ran for a minute or so before cutting out.
Another 6 primes and another start before cutting out after a few minutes.

Today I am again priming a few times and starting but each time it will only run for a couple of minutes.

It would seem that there is air in there still but can it still be after so many purges and running? Or is it possible that something has failed during all of this work? The pump is noisey and may well be original on a 53 plate so I'm thinking that all of the purging has tipped it over the edge but, before I go spending money, can anyone suggest something that I may have overlooked?
Click to expand...
 
Alpinejim said:
It would seem that there is air in there still but can it still be after so many purges and running? Or is it possible that something has failed during all of this work? The pump is noisey and may well be original on a 53 plate so I'm thinking that all of the purging has tipped it over the edge but, before I go spending money, can anyone suggest something that I may have overlooked?
Click to expand...

The other week I had an issue on a D2 TD5 I was servicing for my Father., changed the fuel filter , did not prefill the new one, restarted it ran for a few minutes then stopped, then would not restart.

I pulled the fuel return line from the head (15P engine) to the FPR and stuck it in a bottle. Turned ignition on and only got a small amount of fuel out, compared to mine which I did the same and used as a reference, mine filled the bottle quickly. The actual flow rates are in Rave. Pump was "running", but HP side was knackered. changed the pump for the ine form my car and it started on the button.

Cheers
 
Huddy44 said:
Silly suggestion but I have seen it before....

You have deffo got the fuel lines connected back on the correct way, feed and return?
Click to expand...

I made a note of which went where before taking them off so they're in the right place - unless I messed up my notes.
Looking from the front, my left fuel line coming from the tank goes to the bottom of the fuel cooler (Eu3 type).
The right line goes to the top of the fuel reg. and the bottom of the fuel reg goes to the top of the cooler.
 
Neilly:
I have two other Discos from which I can swap parts but I hear that fuel pumps change from one model to another.
I have Y reg which may be close enough to my 53 plate so I'll give this a go.
It would seem odd that the pump suddenly decides to give up but maybe pushing air around the system is not good for old pumps.
 
I did forget to connect one of the fuel lines in the beginning and fuel pi**ed out when I turned the key.
I'd say that flow was good but can't say how much pressure there was. It could be that there's not enough pressure from the pump despite what looks like a heavy flow.

What would be the symptom of a dodgy fuel reg? It wouldn't reduce flow further would it? Just start leaking?
 
You could double check the fuel pressure. Easy enough to do if you have a gauge.

Only thing about you saying it pi**ed out, is If fuel starts leaking for any reason, even if it is a small amount , it always seems a lot when it happens and you do not want it too.....LOL.


There are iirc 3 videos in this series, one of them shows the pressure being checked.



Cheers
 
Alpinejim said:
I don't have a guage to check pressure so I'm going to start swapping bits until I fix it.
Click to expand...

Just in case you do another flow check.
upload_2017-9-4_9-52-38.png


Cheers
 
Today I swapped the fuel pump from another car. It's still noisy and possibly older that the one I took off but I got the same symptoms - runs at tick over for 20 mins then dies.
I think the next job is to take the fuel reg. block off and swap the reg. itself.
This reg. & block came straight from my old engine where it worked perfectly so I don't see why it might have a problem but what also could it be?
 
It would be good to have a pressure guage to measure the high pressure line.
That chart says 1750 bar, I'm not sure if find a guage to measure that high though.
 
Hi @Alpinejim , Stupid question /thought

But can you change the Crank sensor? I had fuel starting issues, it was my fuel filter housing was knackered , However at exactly the same time my Crank sensor went and left me stranded on the Mway. I could drive for 15 mins and then stopped dead.

Only found it when i connected the nanocom. For 5 mins it is an easy thing to swap.

Cheers
 
Alpinejim said:
It would be good to have a pressure guage to measure the high pressure line.
That chart says 1750 bar, I'm not sure if find a guage to measure that high though.
Click to expand...

You only measure 4 bar at the head, the rest of the pressure is mad internally in the injectors. If you watch those videos you will see that being done.

Cheers
 
Oh yes, of course. I've only just seen that the videos are there. They didn't show up before.

It's a good point about the crank sensor. This is the one on the bell housing right? As I put the engine back in I could well have hit it with the flywheel.
I had figured that if the car runs then I didn't hit it but now you say yours ran for 15 mins then that pretty much what I have too.
 
Alpinejim said:
Oh yes, of course. I've only just seen that the videos are there. They didn't show up before.

It's a good point about the crank sensor. This is the one on the bell housing right? As I put the engine back in I could well have hit it with the flywheel.
I had figured that if the car runs then I didn't hit it but now you say yours ran for 15 mins then that pretty much what I have too.
Click to expand...

The only conclusion I could come to on mine was that it became a temperature issue. Yes it is in the bell housing. Wiring can also be damaged.

Once the car was up to a certain temp the engine stopped, would not restart, I left it 10 /15 minutes and it would restart without a problem , then 15 minutes later ...Stop again. As said, I also had a dodgy fuel filter housing , So it took a bit of hunting to find the Crank sensor issue.

Worth looking at if you have another vehicle with one Crank sensor going spare at the moment.

Cheers
 
Well I changed the CPS today and it's made no difference, it still idles for about 20 mins before dying.

My next theory is the injector seals. They were all replaced when I built the engine up but I find that the fuel pump gets noisier just before the engine dies, like its struggling to pump against a growing pressure.
If a seal is leaking gasses then it would pressurise the fuel rail until it overwhelms the pressure coming from the pump, would anyone agree?
Or would it cause the fuel regulator to close off which prevents to fuel pump from pushing? The effect is much the same I think.
With gas pressure in the fuel rail the engine will die and there's no new fuel available until I purge the system again.
 
This is now fixed!
It was the injector seals. Actually, I had not torqued the injectors correctly which resulted in poor sealing and a build up of pressure in the fuel rail.
With new seals and correctly torqued to 33NM, it's now running well.
Thanks to everyone for their input.
 
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