Starting Issue

Soldato
Joined
22 Mar 2009
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7,754
Location
Cornwall
I have a MK4 GTTDI ARL (PD150) 2003. Love the car and really want to get it sorted so would appreciate any help

Basically, when you try to start it you can hear the starter motor try to turn over but it doesn't turn over. If you try for long enough sometimes it does turn over but quickly dies. But more often than not it won't even start.
If however you keep your foot on the accelerator 9/10 it does start, but, the revs sit at around 800-950 rpm (foot still planted to the floor) for a few seconds before the car revs. On starting a big puff of white smoke comes out and then goes, only get a single puff never a stream of smoke. The garage where I work says it sounds like when it starts the cylinders are delayed (think they said it starts on 2 cylinders then a 3rd followed by the 4th).
Also, until the engine is warm the car idles rough and you can feel a vibration through the car (juddering), nothing major but its definitely there. This seems to go, or at least is less noticeable when the engine is warm.
If the car is not left for too long between starts then it is easier to start, but you still need to press on the accelerator most of the time.

I have VCDS Lite (Registered), are there any blocks I can log whilst starting the car to see if it is a) requesting the right amount of fuel (without accelerator pressed) and if so, are the injectors getting the right amount at start (has been suggested maybe air is getting in the fuel system and pressing the accelerator is possibly shifting this quick enough to allow it to start). Maybe there is a block to measure cranking (although I have replaced the crank sensor it was with a second hand one, could this cause it?)

Sorry bit of a long and hard to read post, hope it makes some sense
 
Associate
Joined
31 Jul 2011
Posts
206
Can't help much more then, sorry. Just the symptoms you describe fit non working glow plugs perfectly. The white smoke is unburnt fuel so the fuel is being injected but not burnt, so you can rule out air in the fuel as if that was the case it would be injecting air not fuel so you wouldn't be getting smoke, The crank sensor gives the ecu the engine speed so if that wasn't working it wouldn't start at all.
 
Soldato
OP
Joined
22 Mar 2009
Posts
7,754
Location
Cornwall
Blocked EGR?

The outside of the EGR looks very clean so I think it might be fairly new although there was no receipt with it for that when I purchased the car so might not be new. I was planning on removing it at some point soon to see if the inlet manifold needed a clean as apparently these are prone to gunking up so will have a look then.
 
Associate
Joined
2 Mar 2016
Posts
43
Location
UK
Tandam pump allowing air in, was the fuel filter black and oily?
A decent diagnostic garage would check the low pressure circuit for problems, or just put some clear line on the return side and you'll see the bubbles.

Daz.
 
Soldato
OP
Joined
22 Mar 2009
Posts
7,754
Location
Cornwall
Tandam pump allowing air in, was the fuel filter black and oily?
A decent diagnostic garage would check the low pressure circuit for problems, or just put some clear line on the return side and you'll see the bubbles.

Daz.

I didn't change the filter myself it was done by a colleague so not sure. Will invest in some clear fuel hose to check for bubbles. Annoying thing is I connected laptop and VCDS up this morning to check the fueling on startup and thing started without the need to use the accelerator. Disconnected laptop and VCDS, cleaned out boot of car, went to start it again and would the thing start :mad: so didnt get a good log of it struggling :(
 
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