Non starter help needed!

[andyg plym]

Ok so here is the story,where the ecu connects to the loom under the dash i appear to have a loose connection (someone has been there before i think-as that sticky black nylon stuff has been tampered with),its run fine for years like this.
Anyway,I noticed one morning the car would not start,I left it then the next day traced back the work I had done and I had just replaced the chips.
So I unplugged the ecu,plugged it back in and boom-it started.
So then the next day after no time to diagnose I drove it-fine,no problems until I pulled up at a set of lights when it died,I leaned down to the ecu wiggled it and it started.
Today same thing,drove to work fine,tonight would not start.
I wiggled,nothing.I even unscrewed the plastic ecu large plug to see if any wires had popped out.....nothing!
So just had the car recovered home and now borrowed a code reader to try and get a head start (Thanks Tristan aka merlin s4)
Anyway,battery almost dead but still got ignition light on and went to connect the ob codereader and that doesnt work

Checked all the fuses for motor etc in the fusebox.

Any ideas?

[andyg plym]

forgot to mention,the ecu clicks ever time you go to start the engine,i cant hear the fuel pump priming but then i couldnt the other day when it was starting,

[ManiacuV6]

Check the relay that gives supply to the ECU. Try to measure on the connector that goes to the ECU if you have all the suplly 12V ( permanent and swiched ) . For a better check use a 21W bulb.
Check also the grounds !

[rj scotty]

Pull the cover off the fuel pump relay and see if its closing.

The fuel pump dose not prime on these cars, it's the after-run pump your hearing. I runs for a few seconds when the ignition is switched on, I'm not sure why it dose this

[andyg plym]

cheers guys,ive just been reading up on s2 central and it points towards the fuel relay,would this also power the obd black diagnotic port? i cant get the code reader to power up,there appears to be no power to the port,the code reader has a black connector and a white connector,i connec them to the same coloured ports in the fuse box,is his right?

[ManiacuV6]

On the black connector you should have a ground and a 12V line . Check with your multimeter !
You can put 12V from the car's battery or another place. Important is to get 12V and ground.

[rj scotty]

That black connector is also fused i think, can't remember fuse number though

[andyg plym]

That black connector is also fused i think, can't remember fuse number though

21,ive checked and its fine

http://www.s2central.net/motronic_04_fuses_ABY.html

this is interesting,it again points to relay???

[UrS4boy]

That black connector is also fused i think, can't remember fuse number though

Something like 27 and 28 here?

[andyg plym]

Something like 27 and 28 here?

thanks dave,ive studied that pic loads tonight as its been posted before

all those fuses are fine,ive checked twice now

[rj scotty]

Good point, have you checked the motor fuses?

[ManiacuV6]

If you want to keep things simple verify the power supply to the ECU connector .

[rj scotty]

Agreed, always check basics and assume nothing in these situations

[andyg plym]

My question at the minute is if the fuel pump relay is connected to the black diagnostic port? thanks again boys.....typical,ive carried a spare fuse box in my boot for months but sods law no freakin relay.

[rj scotty]

No i don't think so but I do not have diagrams with me.

Ignore the OBD plug for the moment.

To Do:

Check motor fuses
Check power to ecu
Take lid off fuel pump relay and see if it closes on cranking