2002 A3 1.9tdi ASZ prolonged cranking before starting hot or cold

[ashton179]

im close to throwing the towel in with the car but someone may have experience of a problem like this before that may be able to help
its a 2002 a3 1.9tdi asz which everytime takes a long time to start sometimes up to 20 seconds and sometimes i have to try a couple of times
if it cranks for a long time the traction control light will come up and will post 2 codes in the ecu
1-engine management - p0322 engine rpm sensor- g28 no signal
2- abs- 01314 engine control module read trouble codes intermittant
i have been through the mill trying different things but to no avail. so far i have replaced
-new battery
-starter motor checked
=-glow plugs changed, circuit checked
-ignition relay 109
-new lift pump in tank
-new fuel filter
-one way anti-drain back valve fitted for fuel
-fuel system additives
-x2 genuine vw crankshaft sensors
-wiring and plugs checked for crank sensor plus visual inspection of pickup ring
-timing checked on vag-com and visually
-x2 new coolant temp sensors
-de-immobilised ecu in exchange for mine
-injector no.1 replaced as was out of line on the idle control
-all other service items new
the fault codes are really saying to me that the crank sensor signal is poor / weak and so not triggering the injectors to open
hence causing poor start, however the other abs fault code was screaming ecu but has now been replaced and still the same
the issue is from full running temp of first start
it screams a weak crank sensor signal but then runs adream once started and never misses a beat, surely a dodgy crank sensor signal would cause running issues also !

[Alan02]

A Cam - Crank synchronisation may be the problem. If the electronics dont know the position of the engine (timing), there is a prolonged cranking time until it works out the position via only one sensor instead of them both.
You need to do some diagnostics and a scope reading while cranking would be ideal.
Have you had a look at the crank and cam sensor wiring and plugs, as a check?

[ashton179]

A Cam - Crank synchronisation may be the problem. If the electronics dont know the position of the engine (timing), there is a prolonged cranking time until it works out the position via only one sensor instead of them both.
You need to do some diagnostics and a scope reading while cranking would be ideal.
Have you had a look at the crank and cam sensor wiring and plugs, as a check?
i have checked the crank sensor plugs and pins, including wriggle tests with a volt meter. I have checked the ecu pins and the wires to it, all seem to be ok. I stripped the loom back where the crank sensor runs under the battery, but sopped halfway as all the shieliding seems in tact.
the only thing that baffled me is that the 3 wires coming from the sensor to the plug continue 8 inches from the ecu whetre the black and white wites are joined together. Dont know why they do that .
need to get vagcom on the case, does it give more data on cam and crank pickup as our snap-on software gas no data on crank or cam pickup at all,
one other thing to mention is when it struggles to start particularly bad the rev counter can play silly beggers and jump around and then delayed movement to idle revs once the car has alteady started

[stevenbmkiv]

Hi,

I have just had the same issue with my Golf GT TDI ASZ. This followed a recent clutch removal/install because a new bell housing was required after a bell housing swap. Since the garage did the work and put the car together I've had this starting issue.
So far I have only replaced the battery and the G28 crankshaft sensor as the only code that came up was G28 No Signal-Intermittent. Vagtech in Milton Keynes did my work.
They advised the wiring between the sensor and ECU may need checking.
I've read loads of posts like this now so before I start replacing parts like the OP has I am going to remove and clean the ground wire on the starter which connects to the engine block. I'll also clean up the earth points underneath the battery tray.
However, any suggestions will be helpful.
I'm an active ukmiv's member too but not all the experts are in one place so again, any help appreciated from forum members would be most welcome.

Thanks.

Steve