Jump to content

starting 1.4 tdi


Recommended Posts

bit of history first,

1.4tdi 167,000 miles,

used to start ok but now the colder weather has arrived got worse and worse to start,just wanted to start first off then loads of cranking then eventually would start,almost as if you where trying to bleed it,

ok,probably needs new glow plugs,

tested and 2 where no good one was,

so 3 bought from gsf beru make and duelly fitted,

12v at the wiring lasts for10secsapprox all ok according to elsawin,

still a pig to start cranks as if no fuel even though you can hear the "squelch" before you start as fuel pump prims the pipes??

goes to start first time then just goes no way mate!! and then you crank untill eventually it kicks into life,

 

only does this when cold when warm its fine, emmisions good and still returns 60mpg and still goes well,

any idears??????

 

 

 

 

Link to comment
Share on other sites

Yeah it does sound like a battery issue. Thought it might be a relay 109 problem but that sounds like battery all over. 

New battery or try to recondition your old one. Personally, I'd just buy a new one.

Link to comment
Share on other sites

Well the self study program explaines it better, but this is how I understand it. Basically the ECU uses the camshaft position sensor to know where in the cycle the engine and therefore when to inject the fuel and start. If this sensor is on it's way out then is sends the wrong timing information to the ECU and you have problems starting (this is what mine did). If you unplug it, the ECU uses the crankshaft position sensor for the timing information instead. The reason it takes longer to start is because the crankshaft rotates half the speed of the camshaft, so it takes a bit longer to work out the timing.

Link to comment
Share on other sites

You could try the coolant temp sender also as the cpu takes data from several points during the glow plug warm up cycle. Unplug the sender and the cpu thinks it's below 0 if it starts normally that's your problem (do this on an overnight cold engine )

Link to comment
Share on other sites

On 23/01/2016 at 8:32 PM, jon_273 said:

Well the self study program explaines it better, but this is how I understand it. Basically the ECU uses the camshaft position sensor to know where in the cycle the engine and therefore when to inject the fuel and start. If this sensor is on it's way out then is sends the wrong timing information to the ECU and you have problems starting (this is what mine did). If you unplug it, the ECU uses the crankshaft position sensor for the timing information instead. The reason it takes longer to start is because the crankshaft rotates half the speed of the camshaft, so it takes a bit longer to work out the timing.

Camshaft sensor does throw an error code when it's failing though.....

Link to comment
Share on other sites

9 hours ago, Skezza said:

Camshaft sensor does throw an error code when it's failing though.....

Well he hasn't said he has checked it with VCDS...

Edited by jon_273
Link to comment
Share on other sites

bit of an update,

as it has not been cold enough it seems to start at the moment but still sometimes turns over then starts if that makes sense,

no idear what vcds is but had it on a code reader and nothing has come up,

surley if the temp sensor has gone you would not a,get a reading of the temp in the cabin and also b, not get 12v at the plugs that slowly decreases as it is suposed to do,

have oredered a camshaft sensor and will try that

Link to comment
Share on other sites

  • 3 weeks later...
On 24/01/2016 at 0:54 PM, 2mcs said:

You could try the coolant temp sender also as the cpu takes data from several points during the glow plug warm up cycle. Unplug the sender and the cpu thinks it's below 0 if it starts normally that's your problem (do this on an overnight cold engine )

update,

have bought a new temp sender as when i unplugged it it seemed to start a bit better,anyway also bought one of those obd blue tooth readers so i could see what is going on,

put new temperature sender in and i doesnot seem to have made any difference,

also when left over night in -2 the obd reader says the coolant is at 3 degrees,

could this be the problem in that the ecu thinks it is warmer than it actually is so thats why it probably wont start very well when cold?????

also read somewhere could be the lift pumpon its way out????

 

as usual any help please

Link to comment
Share on other sites

  • 1 month later...

update,  update

 

after reading about the same problem on various other forums on cars that also use the same engine,someone suggested it could be the in tank electric fuel pump,

after being stood for over 8 hrs it would struggle to start as if you where trying to bleed it up after changing the fuelk filter,

 

anyway to cut a long story short, fuel pump bought and fitted which by the way was an absolute pig of a job to do,

sucess it now starts no problem and also has a smoother tickover,

 

i believe what happens is as soon as the high pressure engine driven pump grabs hold of the diesel the in tank pump just supplies it to it,and if it fails when the engine is running the high pressure pump still draws from the tank it only needs the intial small amount of pressure to start from cold,

so what must of been happening is the in tank pump was getting weak,

 

 

Link to comment
Share on other sites

I dont think the SDI has a pump in the tank, when i did my injector flush and had the hoses to the filter disconnected  no fuel came out and i was running the engine form a bottle with cleaner
have the glowplugs been tested as 1 or more may have failed

 

ignore, just read the post stating pump changed

Edited by Mobieus_uk
Link to comment
Share on other sites

On 13/03/2016 at 8:31 PM, Sausage said:

The weak pump struggled with the cold diesel fuel then? 

looks like it could be the case but also as engine is not warm a bit more difficult to ignite compared to hot engine,

once the high pressure pump has go the diesel it only needs to be supplied every now and then i.e acceleration and cold starts

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.