Starting problem after timing belt change

[jackgibs]

Hi have posted this question before but I think it was in th wrong forum, so apologies.

So here goes....
I have been using this forum for a long time to help me with my Seat Leon 1.9tdi (ASV) 110bhp.
However I have recently become very stuck and was hoping for some help.
After I stripped some teeth of my timing belt I have replaced both timing belt and head (2nd hand head).
Everything has gone to plan but now the car won’t start (it does run if you use ‘car start spray’) the fuel pumps fine and if the injectors aren’t connected the fuel comes out of the pipe but for whatever reason when the injectors are connected the fuel isn’t coming through them.
The injectors do work as they worked on the old head when the car was running.
Could immobiliser be a problem? If so how can I fix it?
I’d appreciate any help.
thanks

 

[martin j.]

Don't know if this is likely as I'm not familiar with seat setup but if there is wiring plug uncoupled/loose then the injectors won't be getting the signal to open? Something you missed when doing the job.

 

[Muttley]

Injectors on an ASV engine are purely mechanical: only one injector has a sensor on it for needle lift sensing, sending that information to the ECU. All the timing, quantity adjustment and so on is performed in the injection pump unit that is driven by the timing belt.

Which means it is vitally important to ensure that both the camshaft and the pump unit are correctly timed when you change the timing belt. There is a straightforward procedure to follow, using a few special tools to lock components in place, that is detailed in the Haynes manual for the Golf 4, Haynes 4169.

 

[jackgibs]

Thanks for the replies, I didn’t know the fuel pump would need to be 'timed' so will have a look and have a go tomorrow!

I haven’t got a Haynes manual and in hind sight I really wish I had got one before I starting this job.

So basically the injector (with the wire on) is telling the car that the fuel pump isn’t timed correctly and not to start.

thanks for your help

 

[Muttley]

Well...... If the pump timing is out then the injection of fuel will come at the wrong time during the piston stroke so the engine won't run at all. All the physical handling of the injection quantity and timing is performed by the pump itself. The ECU sends signals to the pump which control the position of two actuators that set quantity and start-of-injection: They only have a limited range of adjustment and can't correct if the pump is too far out.

In addition to locking the camshaft, flywheel and pump in specific locations before fitting the new toothed belt, the final adjustment of the point of injection needs VCDS or a dealers VAG diagnostic machine. The pump drive wheel (driven by the toothed belt) is attached to the pump flange by three bolts in slots, and you move them round a little to make that last adjustment, based on the signals reported by the ECU and read through VCDS. If you haven't got VCDS, you could try posting a request in the subgroup lower down in the forum to see if you have anybody local to you who is willing to help.

A basic diesel engine doesn't need electricity to work, older engines had entirely mechanical connections between the accelerator pedal and the injection pump. This is one reason why diesels are better in wet conditions - no HT components (coils, leads spark plugs) to short out.

The needle lift sensor tells the ECU when the injection actually begins and is used by the ECU to fine-tune the running of the engine. The crankshaft sensor tells the ECU where the crank is and so where each piston is with respect to TDC.

This VW PDF goes into a bit more detail about how these engines work

http://www.haywood-sullivan.com/vanagon/TDI/tdi-technik-eng.pdf

 

[virdi]

Did you touch any Fuel pipes? Are you sure you have fitted them back the correct way round.

If it's starting with Easy Start Spray ...maybe there's an air lock in the fuel system and it needs bleeding?

 

[jackgibs]

again thanks for the replies.

i've had to accept defeat and will being gettting a mobile mechanic out to have a look.

we have timed the belt and pump and the fuel pipes are corrected lined up but the fuel refuses to go through the injectors.

hopefully it wont be to expensive!!!

 

[jackgibs]

Hi, just to let everyone know. The reason the car would not start was because the fuel pump wasn't correctly timed. Once I had found the hole and it was timed the car started first time. Lucky I did this before the mechanic came out.

Thanks for all your help I am really grateful.

 

[Muttley]

Well done, and thanks for letting us know. Another feather in the SCN cap

 

[Israar]

Well done mate, your engine sounds like mine, as in the title of it; 1.9 TDi 110 (ASV engine code), is yours an SE at all?

Just curious to know also, when you start your engine, does it start first time or does it take a few tries then start sometimes?

--Lee

 

[jackgibs]

Hi, sorry I have only just seen your message. Yes my one is a SE 1.9 TDi 110 (ASV engine code).

My car used to need a couple of turns to start, so when we fixed it we checked the glow plugs and 2 weren’t working so we replaced them and since then she has started like a treat!!

 

[Israar]

It's perfectly OK mate, no one should expect a response instantly from anyone and I certainly don't anyway!

Same engine as mine then, your problem was down to the fuel timing right? How did you do it and what did you go off to check? How did you find checking and replacing the glow plugs?

I'd like to get mine to start first time every time too haha It's pretty good for starting, though sometimes I get the awkward starts. Here's a short video of starting the car, though it was being good there when it want's to be a pain, it takes a lot longer

--Lee