Car won't start (diesel)- again!

[blackcat 0]

I know it's not corrado related but my diesel golf (mk3 TD) won't start and I want to pick some peoples brains about it!!

 

The car turns over but won't start. We thought it may be the glow plugs but we changed them and it didn't help :roll:

 

So, then we had a look at the fuel sender unit that sits in the top of the fuel tank. We tested it with a multimeter (like it said to do in Haynes) and the resistance was supposed to vary when we moved the sender arm thing and it didn't. (However, I don't know too much about multimeters so may not have been using it right :oops: )

 

I'm going to get a new sender unit anyway to see if it helps but does anyone have any other ideas?? :cheers: :cheers:

[craigowl 0]

No help this - but the only time our diesel failed to start in 16 years on turning over, it was the glow plugs.

 

Good luck with your investigations.

[Walesy 0]

I had this problem with my old non turbo diesel MK3 and it turned out to be a problem with the fuel lines. Best of luck with sorting it out blackcat

[Neil VR6 0]

I had a problem with my Pug 205 TD just like yours and it was a faulty relay (which was a relief as it was cheap to fix)

[Walesy 0]

Yeah, it could maybe be the glow plug relay?

 

Here's the thread I started when I had the problem ....

 

http://the-corrado.net/.archive/forum/viewtopic. ... el+problem

[blackcat 0]

Cheers Walesy, I vaguely remembered that you'd had a problem with your diesel a while back but was too lazy to do a search (sorry :oops: )

 

You said yours was the fuel lines. What did you do/where do you look to check these??

[Neil VR6 0]

It wasn't a glow plug relay, something to do with fuelling I think. The garage fixed it for me :oops:

[Supercharged 2]

Some mk3's have a glow plug control unit but i think yours is relay driven...

 

I take it you've checked the battery etc? how old is the fuel filter? - the have a water filter thing at the bottom your meant to drain off from time to time...

[blackcat 0]

I really have no idea about anything!!! It could be many different things and I have no idea where to start and I need my car back for work :confused4:

 

Haven't checked fuel filter and I have had the car 18months so maybe that is the first thing to try.....

[Neil VR6 0]

Take it to a garage then I reckon

[blackcat 0]

I am really skint right now, trying to avoid a garage if possible. Plus don't have break down cover so would have to pay someone to tow it to garage.

[Supercharged 2]

Ok, go to Halfords / GSF / VW and grab a fuel filter - I'd do that regardless...

 

I'd then get onto checking the relay - not sure if there is a way of checking it in the haynes?

[coolrado 0]

then we had a look at the fuel sender unit that sits in the top of the fuel tank. We tested it with a multimeter (like it said to do in Haynes) and the resistance was supposed to vary when we moved the sender arm thing and it didn't. (However, I don't know too much about multimeters so may not have been using it right :oops: )

 

I'm going to get a new sender unit anyway to see if it helps but does anyone have any other ideas??

the fuel level sender will not effect the running its just for the fuel guage on the dash so you wont need a new sender to make it run.

 

check that you are getting power to the glow plugs, there should be a wire linking all the glow plugs together, set your meter to dc voltage and if it is a manual range type usually set it to 20 volts dc, put the black probe on an exposed metal part of the engine and put the red probe on the connection on top of the glow plug, make sure you are not dangling the leads near any moving parts of the engine and then get someone to turn the ignition to the click before the starter kicks in, the meter should read somewhere near 12v for a second or two, if it doesnt you know the problem is with the glow plug control module/relay.

 

are there any clear fuel lines in the engine bay? and do they appear to have fuel in them?

 

fuel filters are pretty cheap anyway and if it hasnt been changed for a while it is definately worth changing.

[blackcat 0]

I wish I read your post earlier, I have just ordered a new bloody sender from the stealers, and they want payment before ordering so thats £60 down the drain :roll:

 

Had a look at filter and drained a bit off. There are a few clear fuel lines in the engine bay and they have fuel in but also air is coming from somewhere.

 

How is the fuel pumped from the tank to the engine then? (I assumed it was the sender unit as it has pipes with fuel going in and out of it).

[Supercharged 2]

Usually the pump is under the sender unit and the pipes go down to it....

 

Ring them and try and cancel it!!

[coolrado 0]

I wish I read your post earlier, I have just ordered a new bloody sender from the stealers, and they want payment before ordering so thats £60 down the drain :roll:

 

Had a look at filter and drained a bit off. There are a few clear fuel lines in the engine bay and they have fuel in but also air is coming from somewhere.

 

How is the fuel pumped from the tank to the engine then? (I assumed it was the sender unit as it has pipes with fuel going in and out of it).

 

they should still be able to cancel the order and give you a refund though, if the there is a constant stream of bubbles in the clear fuel lines there is probably a leak in one of the fuel lines, this happened on my caddy when one of the fuel lines was rubbing on a metal clip which wore a tiny hole in it, just enough to stop it from starting for more than a few seconds or revving over half way.

is there an in tank pump on it? or is it just a set of pick up pipes and the sender in the tank?

[blackcat 0]

I can't really describe what the unit looks like but there is the arm with the float that measures the level in the tank but there is also another part to it which is what I assumed was a pump, but I don't know.

 

I am going to get the new unit anyway, in a vain hope that it may do something!

 

If this doesn't fix it, then I'm just going to admit defeat and get a garage to sort it out and put the bill on the credit card :roll:

 

Cheers for all your suggestions chaps :D

[Walesy 0]

Cheers Walesy, I vaguely remembered that you'd had a problem with your diesel a while back but was too lazy to do a search (sorry :oops: )

 

You said yours was the fuel lines. What did you do/where do you look to check these??

 

 

Sorry, but it wasn't me who fixed it in the end - the guy I sold it too managed to get to the bottom of the problem, I only knew that it turned out to be something to do with the fuel lines because i'm just about to buy the car back from him :lol:

 

Have you managed to get it sorted ?

[blackcat 0]

Not sorted yet. :(

 

I have a part to pick up from garage today but I don't think it will help. TBH, I'm fed up with it, it's only a crappy runabout which I got as a temporary car about 18 months ago. I haven't got money to throw at it until we find out what's wrong with it. Could take it to a garage and it could turn out to be a minor thing or it could turn out to cost me loads of money, I'm not prepared to take the risk.

 

If I can't get it working tonight then I'm tempted to just ring the scrappy to come and get it.

[peteTDI 0]

i'll have it if your scraping it

[CorradoVR6-Turbo 0]

Best checking the power to the glow plugs first to eliminate one problem.

Check it with a voltmeter or fit a 12volt test bulb from the glow plugs to the chassis earth.Try this with the ignition on and while cranking,power should stay on up to 3 min when cold.

 

The next main problem will be air in the fuel system,the sender on the tank is for the gauge and has no pump inside as the diesel pump draws the fuel in.

 

Next thing is to get a spanner and loosen the injector pipes at the injectors and turn over the engine until you have fuel squirting up at least 3 inches ish,once you have done this then retighten and turn over.

 

If you don't get fuel squirting out,try to remove the fuel filter and fill it up with diesel from a can and refit it and then do the process above again.

 

If all else fails, it is a possible pump fault.

[TomB 0]

Might be worth a post on http://www.vwdiesel.net... a very helpful & knowledgable bunch.

Does it turn over and just not catch? If so, do you get unburned fuel in the form of smoke from your exhaust? If that's the case, it's an ignition rather than a fuelling problem.

As others say, the fuel filter's always worth a punt, and the injector trick that was suggested is a corker. Any visible leaks from the lines under your car? Is there any chance that some pikey get has syphoned your fuel out? (It's happened to me before).

Good luck,

Tom

[blackcat 0]

Yes it turns over just doesn't fire up. And yes, lots of smoke from exhaust.

 

When you say ignition problem, what exactly do you mean? What parts should I be checking?

 

There are no visible leaks and I can't see any evidence of diesel on the driveway. And no, it hasn't been siphoned out by some pikey, there's at least a quarter of a tank in there.

 

I will check the power to the glow plugs tonight although I'm pretty sure that they're ok.

 

I can see air bubbles in the fuel line going in to the filter, is this likely to be a hole in the pipe somewhere or could air get in somewhere else??

[Walesy 0]

i'll have it if your scraping it

 

How very helpfull :lol:

[Toad 0]

Yes it turns over just doesn't fire up. And yes, lots of smoke from exhaust.

 

When you say ignition problem, what exactly do you mean? What parts should I be checking?

 

There are no visible leaks and I can't see any evidence of diesel on the driveway. And no, it hasn't been siphoned out by some pikey, there's at least a quarter of a tank in there.

 

I will check the power to the glow plugs tonight although I'm pretty sure that they're ok.

 

I can see air bubbles in the fuel line going in to the filter, is this likely to be a hole in the pipe somewhere or could air get in somewhere else??

 

There could be a hole anywhere in the system, most probably from one of the pipe fittings. have you changed the filter yet? whilst you're under the car inspect the lines for damage, then I reckon you need to bleed your fuel pump to try to get the air out.

 

Essentially, you must not get air in your fuel system on a deisel as it stops the injectors from injecting. (the fuel pump pumps a certain quantity of fuel up the injector line, the pressure in the injector causes it to open and squirt fuel in, if there is air in the line, then it gets compressed, and the pressure in the injector never increases high enough.)

 

Be very very very very careful with injectors the pressures are high enough in the lines and from the injector to inject fuel through your skin, leading to blood poisoning and all sorts of nastyness, including dying.

 

Try to find out about a bleed screw on the fuel pump, and there should be a manual lift pump under the bonnet. When you find these, undo the bleed screw half a turn and pump the lift pump, it should pump fuel out the screw, and probably quite a few bubbles, keep pumping till the bubbles stop, re tighten screw, and loosen the fittings to one of the injectors, get your assistant to turn the car over until there are no bubbles at the injector. re tighten and it *should* start.

 

Next time, air will have gotten into the system and you'll have to re do this sequence.

 

You will have to find the source of the air ingress fairly soon.

 

Hope that helps..

 

if you still struggle pm me.