Bigt's Big MK 2 project temperature problems.

Hi all,

Wondering if any of you schooled up boffins out there can assist on the one issue halting the completion of my
MK II Gti project. Car has been off the road for 2 years....:facepalm:

We Have replaced the original bottom end with a 2.0 that has been blueprinted and balanced from a donor car , replaced ECU, sensors(including blue temp sensor), belts, Cam, thermostats, Idle control valve, gaskets, O ring, fuel pump, filters etc.

The car starts, and runs until it reaches operating temperature, then dies:mad:. We again start the car and when it reaches operating temperature remove the plug that the blue temp sensor clips into and it runs,but like a dog and very rich guzzling fuel.
What is causing this:confused:? Has anyone out there had the same issue? Spoken to VW and the have NFI!

PLEASE PLEASE guidance and advice much appreciated.

Year model would help.

1990 mk 2 golf gti 5 door. apologies

I know you said its been replaced, but those Blue temp sensors are known to be a PITA.
Grab a multimeter (and thermometre) and double check the value's as shown here,

7. Digifant II Fuel Injection - 7.2 Cold Start and Cold Running Enrichment - Coolant Temperature Sensor

Thanks will do.

Update just came in after the mosquito's had a smorgasbord on me. Inspected the
thermostat believing that to be an issue, listed operating temperature at 87 degrees. Thought that may be an issue, so drilled it as I saw my old one. Put all back together and BINGO, car still died:mad:!

In a final desperate move changed the eath wire for a brand spanker and re-filed the bolts... And once again nothing:banana:!

Monday I will attempt to inspect the sensor again and change it for a new one if required.

Had auto electrician look at the car today and believes it can only be the sensor after testing the wires, plug and ecu.

Sensor comes in tomorrow, lets all prey this fixes the bind I'm in.

Just in case it helps, I had the x2 brown earth wires on the gearbox side of the head that go onto a 10mm bolt shear off. That made the engine run really ritch (black smoke and all).

Thanks ill check that and see currently my earth is mounted on that side.

Changed the sensor today and again no joy keeps cutting out.

Found a wire missing that runs off the wiring of the blue temp sensor. The color of the wires are brown/green and brown and white.

Anyone have any ideas whether the blue temp sensor requires additional wires/plugs to pump up the resistance?

Really lost here.

You may have a faulty ECU, it is a long possibility but I had massive fuelling problems due to a failed ECU in a digifant system.

Hey thanks for the input, but I have already replaced the ECU for a digifant 2 brand new(ha that rhymes)

Anyway there was a loop of wiring connected from the temp sensor to another 2 wires, that were brown/green and brown/black. it used to sit next to the distributor and run from near the radiator fan back up and into the ecu. Cannot for the life of us find a connector or anything of the sort to justify this connection, but it might be my issue. Has anyone with an 8v have a look at the wiring coming from that blue temp sensor and tell me were it all leads to and were it connects with pics please?

Again tomorrow ill go out and stare at the sky and ask why was I cursed.

Cheers