VW Sharan 1.9 tdi PD wont start

[miha99]

Please help, I have a problem with Sharan 1.9 tdi pd 115 hp AUY wont start.In control unit no fault,I have 3,5 bar from pump in tank.I only can`t find info how much is suply voltage on injectors, because I measure 0V from suply pin 114 from ecu when I crank but ecu give negative graund pulse to injectors when I crank.Any idea or info please ?!

[grimmer]

have you checked the pre-heating circuit?

also the lift pump relay plays up on the tdi's and the crankshaft sensor

[miha99]

I check measuring blocks and the crankshaft sensor give engine speed info.I don`t see problem on the lift pump relay or pump because I have 3,5 bar from tank.
Also car start imediately with some help from "start spray"
As I said I don`t have suply voltage on Injectors, so injectors give no fuel !

[alfons37]

check if you have air in the fuel line, have you tried and aeration?

[ammarben]

you have an injector faulty perhaps shortcut to groung
begin by unpluging the injector one by one and crank
engine if it start than you must change the faulty injector

PS:pre-heating work under 0 so it dont mater

[miha99]

@ alfons37 I don`t see problem in (http://www.digital-kaos.co.uk/forums/members/76669-alfons37/)air in the fuel line (http://www.digital-kaos.co.uk/forums/members/76669-alfons37/) because pump give pressure like crazy. (http://www.digital-kaos.co.uk/forums/members/76669-alfons37/)

@ ammarben (http://www.digital-kaos.co.uk/forums/members/97189-ammarben/) I think injectors are OK couse in ecu is no fault and if I disconect plug ( from picture and measure pins when I crank than 5,3,6,2 give negative graund pulses to ecu but on pin 7 is nothing and I think there must be suply for injectors !!!

[ammarben]

dont disconnect all injectors
disconnect one by one ; I am sure you have one wich is not good i have repaired a jeta PD like this
after disconnecting the faulty injector the car start

[ammarben]

pin 7 is ground for all injectors
cut or disconnect first pin 2 and crank the engine if it start that's good you have found your faulty injector and so one
3;5;6

[miha99]

And in your case you don`t get any fault code for injector in ECU?
Are you sure pin 7 is Ground because it go to motor ecu to pin 114 and what must be on pin 2,3,5,6 +12V or pulses or what?

[ammarben]

i think ;because i forgot; that pin 7 is +12v and on pin 2,3,5,6 pulses by ecu

[ammarben]

as i have said to you dont scary disconnect pin by pin 2,3,5,6
first start by disconnecting pin 2 and try to start
after that connect pin2 and disconnect pin3 and try to start
by this way you can found the faulty injector

[sepistar]

check diesel filter it have to be full,if not no diesel come from tank.then check relay 109.
best regards

[miha99]

@ ammarben I try your metod ( (http://www.digital-kaos.co.uk/forums/members/97189-ammarben/)disconnect pin by pin 2,3,5,6 and start) but no success. (http://www.digital-kaos.co.uk/forums/members/97189-ammarben/)

@ sepistar (http://www.digital-kaos.co.uk/forums/members/192030-sepistar/) Filter is new, relay 109 cheked also all suply voltages and graunds to motor ECU are OK!

Like I said theres no suply voltage to injectors from ECU (from pin 114 on motor ecu) and I also cant find any info about it, not in autodata, workshop vivid, toleranca or esi tronic !

[ammarben]

you said " ecu give negative graund pulse to injectors when I crank" that is good ECU work fine so pin 7 is not feed by +12V

[miha99]

Yes ECU not feed injectors with +12V also I try with two ECU and ECU is not a problem.

[ammarben]

your problem is the wire between pin 114 from ECU and pin 7
of injectors connector
test the continuity probes of ohmmetre put one in pin 7 and
the other probe in pin 114 from connector of ECU

[miha99]

Sorry mate all connections from ECU to injectors are OK, I duble check all lines.

[BRAVO6]

Like I said theres no suply voltage to injectors from ECU (from pin 114 on motor ecu) and I also cant find any info about it, not in autodata, workshop vivid, toleranca or esi tronic !


Pin 114 is ground connection for injectors. This engine is reverse of usual setup. ECU pulses positive power to injectors, pins 2,3,5,6.

[Ashraf6119]

Hi

Pin 114 is a Brown Wire which means its a (Earth) Ground wire for all Injectors.

Can you test it at the injector plug to see if you have signal by using Niod Lights............

[miha99]

Thanks a lot for that infos, I will check on monday.But it confuse me because when I measure with probe lamp from +12 from battery to pins 2,3,5,6 (with unplugged injector connectors) than lamp flash in pulses when I crank the motor.But if I crank and measure with probe lamp from pins 2,3,5,6 to negative graund than lamp don`t flash also no voltage if I measure with voltmeter.And I stil can`t find any info for Voltage on injectors when motor crank?!

[ammarben]

Piezo injector failure seems mostly due to an internal electrical fault in the Piezo valve. The internal piezo wiring seems to burn out and short to the casing. The Piezo valve voltage signals are 100 -200V. Rather than risk damage to the ECU when one ?shorts?, the ECU switches them all off.
The engine will cut out instantly and will not restart.

[Ashraf6119]

Piezo injector failure seems mostly due to an internal electrical fault in the Piezo valve. The internal piezo wiring seems to burn out and short to the casing. The Piezo valve voltage signals are 100 -200V. Rather than risk damage to the ECU when one ***8220;shorts***8221;, the ECU switches them all off.
The engine will cut out instantly and will not restart.


ammarben,

I do agree with your suggestion but, only if this was an 2.0 Lt engine.

But, according to the engine code this is an 1.9 Lt engine and it as other type of injectors which I have not seen any day to short to ground like the new ones.



Miha99,

And the injector voltage info is when cranking you should have at-lease 2.5 volt that's why I said testing with Niod Light is the best option..............

Can you please confirm is the injector in the picture I posted looking same as in your car or ????

[calin_bm]

do one thing, unplug the G62 sensor,and see what happens,please report if you check,i'ts the simpliest test to do on your car.

[miha99]

Hey Ash I attach picture of injector and I also ordered noid light kit.So if I measure with oscilloscope than peak voltage must be bigger than 2,5 volt?

Calin, I will try to disconnect g62 sensor to see what happens.

[miha99]

Problem solved, replaced all 4 injectors and car start immediately.

[ammarben]

that's what i have said to you in the begining
you have a faulty injectors

[miha99]

Yes mate I tried your metode but there was more than one faulty injector so disconecting one by one didnt solve the problem.