1.4 Tdi Struggling to start..

DaveySprocket

DaveySprocket

A2OC Donor
Hello folks, I'm just getting stuck into finding out why my newly acquired A2 is having such a hard time starting, I changed the fuel filter first off, thinking it would be an easy fix, but it has made no difference at all. The problem does seem like it is fuel related, as in not enough fuel getting through.

This was the filter, so I guess it hadn't been changed for some time.
IMG_20231124_100652_HDR.jpg


I've just done a scan and got the following message:
IMG_20231127_122336_HDR.jpg


Probably not the main problem, but something that needs sorting anyway. The glow plug relay has been bodged up as well, so will order a new one of those.

I've looked up to find out which relay is the glow plug one, seems like it should be the one marked 614 on this photo?
IMG_20231127_120900_HDR.jpg


I've had the battery on charge for at least 12 hours and it's not fully charged, so it might be knackered as well. I've got a tester so if it ever shows fully charged I will check it out.

Otherwise on my to do list are:

Fuel tank sender
Earth points
Tandem Pump
Crankshaft position sensor
Injector Loom
Genuine Fuel Filter

Being a bit hampered by the rain today, but I'm taking the opportunity to familiarize myself with the car and where everything is!
 
I've seen fuel filters looking much worse than that, but the fuel filter drain plug screw is sheared off so unless you have fixed that then it will be probably drawing in air, and leaking.
The glow plugs definitely help starting but except when it's really cold most cars will start eventually even with only one working. A clue is usually some smoke when it finally starts as the unburnt fuel catches.
It's definitely worth checking the camshaft position sensor as they can cause starting issues, as can the crankshaft sensor.
 
AndyP said:
I've seen fuel filters looking much worse than that, but the fuel filter drain plug screw is sheared off so unless you have fixed that then it will be probably drawing in air, and leaking.
The glow plugs definitely help starting but except when it's really cold most cars will start eventually even with only one working. A clue is usually some smoke when it finally starts as the unburnt fuel catches.
It's definitely worth checking the camshaft position sensor as they can cause starting issues, as can the crankshaft sensor.
Click to expand...
Thanks Andy, I have bodged the drain plug with some washers, O rings and a M10 bolt for now, so I am confident that isn't the problem. Ordering the fix from Depronman is on my list though!

I'll do some research on the sensors you mentioned.

Cheers, Dave
 
So I got the sender unit out today, which was easy enough. I was surprised how big it was, it's not a small unit! The whole thing was completely black on removal, as per the second photo.
IMG_20231128_135944.jpg

IMG_20231128_140501_HDR.jpg

I blasted everything with carb cleaner, especially the plastic pickup filter on the bottom which seemed to be fairly blocked with crud, which could well cause the starting problems I am having.
IMG_20231128_142322.jpg

IMG_20231128_142315.jpg

All cleaned and ready for reassembly. I'll get this back in tomorrow, and see what happens, fingers crossed!
 
Afternoon Dave,

A belated welcome to the Club Sir. Very well done on getting to the bottom of starting issues so quickly. When swapping my fuel sender some months ago I too was quite shocked at how covered it was in the black film. Like you, I resolved this with a quick squirt of cleaning agent.

Personally I didn’t have any starting issues as I was only in this area of the vehicle to add a later revision fuel sender to pair it with the later production instrument cluster I retrofitted. It does show that this build up can cause fuel blocks though, probably why many early TDI owners suffer Webasto woes. I’m guessing adding further additives to the fuel tank like 2-stroke oil would speed this deposit build up.

Well done and welcome again.

Kind regards,

Tom
 
DaveySprocket said:
I put the sender back in this morning, its 2 degrees outside, the glow plugs don't work, and she's starting on the button, happy days!

For a repair that cost nothing, I am seriously chuffed with that result. So easy to do as well..
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Wow. I'm really surprised, and very pleased for you that cleaning this up made such a difference. That mesh at the bottom of the sender must have been blocked solid. Even if it was blocked solid I'd have expected the hole that is opened up by the float to allow fuel in from the bucket to supply sufficient fuel for starting. Unless that was blocked solid (or jammed) as well.

Great fix which is sure to help others in the future.
 
I just tried it again this morning, and it started on the button, so I am now fully convinced it is sorted..

My sister was running the car like this for maybe a year, it always started eventually, but normally with difficulty. She lives a long way away and I don't have loads to do with her, so I was only vaguely aware of what was going on. I know various mechanics had tried to sort it, one lot broke off a glow plug and then denied all knowledge, so she then had to pay for that to be fixed. This is why I do stuff myself these days, with the help of forums like this, a bit of Youtube, and the willingness to dive in, it's surprising what you can do.

I was telling an A2 owning mate about it last night, and his is a bit sluggish to start. This morning he took his sender out, and it was as clean as a whistle, so no easy fix there.

A bit of a random and lucky fix I know, but I'll take it, as everything else on my list was going to be a lot more complicated.

Just got to get the drivers door opening now, sort the wiper mechanism, and get a new windscreen, doh!
 
Well the car worked fine for while, so I lent it to some friends for a bit, and I get a phone call, The car won't start, doh!

So the fault is back, struggles to start. Still seems like fuel, but I popped out the sender unit again and it's clean as a whistle. I was thinking I should drain the tank and clean it, but maybe not.

So now I don't know if I'm on the right track, or whether I'm looking in completely the wrong place. I'll do some more research on the other possibilities I guess, which are:

Tandem Pump
Crankshaft position sensor
Injector Loom

Any thoughts or ideas would be gratefully received, cheers, Dave
 
New list :)

Tandem Pump
Crankshaft position sensor
Injector Loom
cam sensor
injector seals

I'm just doing injector seals on a Peugeot, and it is very noisy and blowing smoke, so not so likely on the Grey Dolphin, but mustn't rule anything out at this stage. Thanks Phil!
 
Is the glow plug relay fixed yet? Although you will get varying degrees of opinion as to how important this is, it makes sense to fix what is known to be broken first.

Next thing I would do is fit a clear tube into the tandem pump return line. Have an assistant try to start the car and watch for air bubbles in the clear plastic tube. If you see any air in the fuel during cranking or after starting (keep watching for at least a couple of minutes)then air in the fuel is your starting issue. If no air at all in the return line only then would I start checking your list.
 
Yes I did get a new relay fitted!

Thanks for your suggestion, so if I do as you suggest, and have air in the fuel, does that mean an issue with the Tandem pump, or air getting in from somewhere else?

Thanks, Dave
 
I've found this link to clear hose, but not sure what size is required, anybody out there know of the top pf there head please?
www.thehosemaster.co.uk

Clear PVC Diesel, Oil, Fuel Hose

This is a transparent unreinforced PVC tube designed for Petrol, diesel, oils and biofuels. This is suitable for fuel lines on motor mowers and similar light duty non-pressure applications.
www.thehosemaster.co.uk www.thehosemaster.co.uk
 
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Have the glow plug system checked for correct operation and the plugs replaced with the correct ones if needed.

Air in a diesel fuel system is very bad. Not only do all pipes have to be in good condition each and every connection has to be tight and with the correct type clamp to ensure the force is distributed correctly. The fuel filter also needs to be air tight with intact OEM or better Paul's bleed screw and the housing not cracked. For earlier ones with the metal canister all connections need to be good and the temperature valve "T" must not leak fuel. The tandem pump must be externally dry with no signs of leaks ( oil or fuel ).

Now with a short length of clear fuel tube fitted between the INLET fuel pipe and tandem INLET port start the engine and observe the fuel in the pipe. If large amounts of bubbles are seen then you have an air leak in the system that needs to be found and sealed. Now stop the engine and observe the clear pipe, if the fuel level can be seen dropping back down the pipe then the tandem needs replacing. This may happen slowly so check back every so often.

Once all diagnostic checks are done it is important the fuel pipes are refitted and sealed. Also if you remove any pipe it is critical that spilt diesel is not allowed to come into contact with any rubber component as it will destroy it very quickly.
 
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