car not starting

[fazzogs]

hi my 89 rallye has start probs. it just turns over without starting. the rac came out and hard wired injectors as no power was going to them and the car started. located injector relay and replaced vw part. also replaced the ecu relay no 30 but still the car will not fire. fuel ok, spark ok. is it possible the ecu itself has gone? any suggestions. thanks

[Chris S]

Given the age of our cars its more likely to be a wiring fault, but again it could be the ECU, do you have access to a different one to try?

[fazzogs]

no do i need rallye specific ecu, will try to locate one on web but will follow wires first. will let you know

[Chris S]

You need a G60 specific ECU, anything with the following part numbers will do.

037 906 022 EH

037 906 022 EG

037 997 022 X

like this one

http://cgi.ebay.de/Passat-Corrado-Golf-G60-Motorsteuergerat-Motor-EH-Bj-97-/120580704425

[fazzogs]

thanks chris, had an auto electrician look at it, power going to injectors, he thinks if power to injectors, you have spark and fuel must be the injector rail itself. are they known to fail?

[Chris S]

Not really, but there again they are 20 years old now.

[Audi Doody]

Hi, I have circuit diagrams for the injectors if you need them.
if you have 12v on the injectors then the signal from the ecu might be broken. All the injectors are fired together at the same time, check for continuity from pin 12 on the ecu to the injectors. wire colour is grown/yellow at ecu and brown on injectors. if that is ok and you have 12v then best guess is the ecu must be at fault.
Seems strange to me that the RAC bloke got it running by rewiring the 12v feed?

[fazzogs]

thanks, will follow and see what the outcome is. fazz

[Audi Doody]

Just had another thought, there is a 2 pole connector that has the 12v supply and the injector control from the ECU. If this connector is corroded, it might cause the problems you have.
the wire colours are:-

pin 12 on ECU– Brown/Yellow–(connector T2a/2)–Brown–injectors
and
Z1 on fuseboard–RED–(connector T3c/3)–RED–(connectorT2a/1)–Red–injectors

this bit I hope Chris can help with….

connector T3c is located:
3-polige stecker, links in watervangbak
3 pin plug, left in the water catch tray

connector T2a is located:
dubbele steker, bij inlaatspruitstuk
2 pin plug by the inlet manifold

sorry my Dutch is crap and so is Google’s……..

hope this is some help,

Mike

[fazzogs]

thanks mike, will exhaust of the above to see if it is sorted. fazz

[fazzogs]

ok inoticed fuel pump was not coming on, has done previous so checked fuel pump fuse it was not blown but there was no volts to it. the relay is new as well. the fuel pump was not coming on when ignition was turned.
no volts on plugs leading to injector rail or pin 12 on ecu.
put a earth feed on pin 3 ecu and the fuel pump came alive. car turned over and checked fuse for fuel pump and it was running 13v. car continues to run whilst earth is on pin 3. when earth is removed car stalls.

question, is problem within ecu circuitry? there is power on other pins so assuming power in is ok.
the other thing i noticed was the top of the ecu that flips open so pins can be seen, if this is moved whilst car is running with the direct feed to pin 3 then car stalls. so i am assuming that there must be circuit problem.
there are companies that repair ecu’s may give them a call’

any other idea?

[Audi Doody]

Hi Fazz, difficult to understand..is it the top of the ecu connector coming loose? photo would help. I would check the connector..anything contacts greencorroded or black from arcing? clean them up and try again.
if you are happy that the connector is ok, then all that can be left is either the ecu is fried or something odd like an old alarm is causing problems.
try connecting a multimeter to look for an earth on pin 3 and gently tap the ecu…might show up a bad solder joint.

mike

[Audi Doody]

final thought, in the depths of my memory I remember something to do with the earth connection from the ecu on the engine block.
now this might be a load of rubbish but it goes something like this.

Main earth for the ecu comes from the engine block and it breaks,the ecu continue to work via an earth braid from one of the sensors, only the braid is not man enough to handle the current and starts to break down causing intermittant running and eventually the engine stops working.
now this might be another make of car or as I said a load of rubbish!!

maybe someone can confirm this?

mike

[fazzogs]

tried to put up picture but having difficulty. when you take the ecu out it has a square panel on top which is held down by 2 screws. when the screws are removed the square part lifts off and is still attached by a ribbon of wires. the pins are now exposed. its this ribbed wiring where i think there may be a cut as when this is moved there is a cut in power even when pin 3 is directly fed.

will try to source ecu but will continue trouble shooting. thanks for the help so far.

[fazzogs]

thanks all for your input. finally located fault.– no earth to fuel pump relay. located earth wiore into the fuse box for the relay and temp spliced a fresh earth of body work into wire that feeds relay. hopefully solves problem.

[Author]

Posts