1.9 TDI starting from cold problems

[martincloud9]

Hi there

I have a 1.9 TDI Leon and it has always had a starting problem since initially purchased.

The pre-heat light (for the glow plugs) on the dash board never stays on, i have so far had it in the garage (NOT Main dealer) 3 times trying to solve the starting problem, so far the following has been checked and ok'd

(The only way we can get the pre-heat light to stay on for any length of time is to disconnect the temp switch, then the light stays on for the described 2/3 seconds).

So basically the car seems to think the engine is constantly warm and therefore the glow plugs are never told to kick in! Luckily the car does start from cold without the glow plugs however it cant be doing ity much good! The car runs perfectly once started.

So, glow plugs are now new and in full working order, wiring has been checked by auto electrician and all ok and new temp switch has been added. but still I have problems.

Anyone have any ideas or heard of this type of problem before? Someone has suggested something to do with the pump timing, does that sound right?

 

[volvic]

Hi Martin,

When you say it has trouble starting how does it actually start? After a few cranks? or more?

It's a shame we have glow plugs, as some diesels retard the timing to get the engine going. Would of been one less thing to worry about!

 

[martincloud9]

some mornings it takes up to 30 seconds or so to get going, but once it goes it it runs clunky for a second, then runs perfect.

erm, also, you need the glow plugs to heat the diesel, not sure retarding the timing would help either way.

I have found lots of people with this problem, but I can't find a solution. Anyone acually solved this problem?

 

[volvic]

erm, also, you need the glow plugs to heat the diesel, not sure retarding the timing would help either way.

nicked from how stuff works, the diesel is not heated the chamber is

Glow plugs are rarely used today on larger engines. The ECM senses ambient air temperature and retards the timing of the engine in cold weather so the injector sprays the fuel at a later time. The air in the cylinder is compressed more, creating more heat, which aids in starting.

hope you get to the bottom of this!

 

[richellis]

Ive got this, could it be glow plugs, and if so would they show on vag com??

 

[martincloud9]

Ok, for me it is not the glow plugs. I have had them all replaced. I have had the temp sensor replaced, wiring checked etc.

My car is a 2004 model (hardly ancient) and has glow plugs. Must be a very recent change to not have them. Most of the people I know who work on diesels said they have not come across a car without them. Even the newer ones...
Anyway, no point talking about this part.

Out from all the people on here, and the people with this car, has anyone resolved this problem?? If you have, can you please tell me.

Thanks

Oh, gonna buy a VAG com thing. If I find an answer I shall be pleased to write it on here!

 

[sykesytdi]

to be honest mine aint the best from cold..... starts ok but seems to run rough for 20-30 seconds then its ok.... i was told all diesels are crap when cold??

 

[richellis]

Its still under warranty so Ill give the dealer a call in the morning. Not right as it has only started playing up over the last week. Was fine in the very cold weather, and its garaged.

 

[andycupra]

i dont have great knowledge of diesels. but i thought glow plug lights come on then go off to indicate you can start. so the glow light not staying on is normal?

 

[martincloud9]

After some painstakingly long research, it appears this could be a poorly set up injection timing system.

Apparently garages normally just check if there is a code wrong and not bother checking the settings.
Have you had your belts changed lately? I had mine replaced because the cam wore through the tappet and I needed a new head and had the belts replaced then. (£2000 after 6 weeks of owning)

Suggestions are: to use the vag-com and check if the timing is correct. oh, and I got the temp sensor checked too. apparently if it's reading wrong it doesn't produce a code but it can tell the ecu the engine is warm when it isn't!

Will post the results when they happen.

 

[martincloud9]

Ok, VAG-COM said the timing was fine and well within tolerance.

Took it to a Bosch 'specialists' in Hoddessdon, they replace the injector seals without testing the emission's, timing, fault codes etc.
They say it is fixed, I go there, start it up before paying. No change.

Next day they tell me the pump timing is out a little (thought it couldn't be from what I have heard about PD engines...?), they say it still isn't working right.
Next they say they were just guessing from now on. Taking the injectors out (again) and get them tested. I asked why they didn't do it when they were out last time. Apparently they don't have the equipment to do it.....???? So if I were to swallow the cost: £300.00 for testing if they work, but then more if they aren't working.

"They are specialists, diesel specialists!!! Why don't they have the needed equipment to do their job?? they didn't even have the seals in stock!"

So, SEAT cannot fix this problem. A Bosch specialist can't fix it. There is a problem, everyone admits it. What do I need to do, buy a new engine?
I'm can't keep paying more money out to people to tell me that they don't know what the problem is.

What about just finding some injectors from the scrap yard and just changing them over to see what happens?
How hard is that? Could I do it myself? (I have changed over cylinder heads and pistons
in my past, just hoped those days were behind me now!)

 

[ryan106]

I don't know much but my input would be to check the voltage you are getting the glow plugs to ensure these are operating correctly also if it takes a while to churn it is possible it is fuel related and maybe the fuel isn't ready in the pipes small hole etc and the churning is a way of getting the pump to drive the fuel back up the system, not sure if you have one but if you have a primer bulb prime the diesel up then try to start. Glow plug relay maybe.

 

[martincloud9]

All the electronics are working fine, this appears to be mechanical.

After lots of digging, there are two other approaches. The injectors might need cleaning (must admit I put injector cleaner in twice, and both times the fuel economy went down. Didn't add the two together until now.) Plus there is a site mentioning something to do with getting the injectors set up with the new cam http://uk-mkivs.net/forums/p/245525/1602833.aspx

The system doesn't have leaks, it can't by now. All seals have been checked and replaced.

It's a real noggin scratcher, but I'm no quitter. I might just go and cry in the corner for a bit though......

 

[martincloud9]

The EGR light has come on. This is something I asked the garage if they had checked. Obviously not...

I guess taking it off and checking is the next task.

What would cause the EGR valve to fail? I know it is soot build up, but what would start it off? poor seal? cracked vacuum pipe?

 

[martincloud9]

Ok, So far the problem seems sorted.

http://www.seatcupra.net/forums/showthread.php?p=2315921

It seems like the car is designed to eventually kill itself. Very poor design!