electrical troubles ..

[trevytrev]

Hi Guys,

My S3C has decided it does not want to start anymore !, engine turns over but I have no spark and the fuel pump is not running.

I have checked all the cables to the fuel pump, the fuel pump relay right up to the ecu and they are all fine, it just looks like the ecu is not sending the signal needed to the relay.

I have also checked my alarm and all the relays on that are working correctly (plus if I don't disable the alarm the engine will not turn over)

This is the point I'm stuck on where do I go next ?, any help greatly appreciated ..

Trev

[bil]

what voltage is at the battery terminals, and is it the same at the ecu?

bil

[trevytrev]

yep same voltage at the ecu and the battery.

[tvrgit]

Check that all the "ignition" controlled stuff is working - indicators, etc. If it is then ignore the rest of this post!

If not then the problem is the ignition switch connector. Take off the lower steering cowl and you'll find a small 4-way connector to the ignition switch. The ignition feed (the red one on mine but god alone knows on anybody else's!) has a tendency to burn out the connector terminals - what happens then is that the key works in the "start" position so the engine turns over, but the coil, the fuel pump etc are getting no juice so no startee.

Replace the connector or even solder the wires together and insulate them, and problem solved.

I fixed this on mine early in August 2003 - there should be pics on my web site diary but I can't look at the moment.

[trevytrev]

thanks all the lights, indicators are working, I have checked the ignition anyway but this is all ok.

further tests show I have power to the coil, I have checked all the earths and power for the ecu and it all seems fine. I have also double checked the alarm and this is also working correctly.

I have just plugged in a fault code reader into the ecu and I get nothing ! - so my thinking is the ECU has died ...

anyone got any further thoughts ?, also does anyone know anywhere where I can take the ecu to be tested or where I can get a replacement !?

Thanks again ... Trev.

[tvrgit]

trevytrev said:

I have just plugged in a fault code reader into the ecu and I get nothing ! - so my thinking is the ECU has died ...

anyone got any further thoughts ?, also does anyone know anywhere where I can take the ecu to be tested or where I can get a replacement !?

My car works fine but doesn't power up a fault code reader either - don't take too much from that...

Before you buy another ECU why not try a swap with a known good one? At least it eliminates another possibility

Edited by tvrgit on Wednesday 30th January 17:04

[ketvrin]

If you decide it is your ECU, these guys seem to keep them and recon them too...

http://cgi.ebay.co.uk/Ford-Granada-Scorpio-ECU-92G...

K

[bil]

are you getting voltages at the throttle pot, injectors etc?

bil

[Le TVR]

Take the fuel pump relay apart and see what state it is in.
The electronics inside that detect the ignition pulses are notorious for reacting badly to damp....

You could always physically close the fuel pump relay and check if it will then start.

[Roy C]

Le TVR said:

Take the fuel pump relay apart and see what state it is in.
The electronics inside that detect the ignition pulses are notorious for reacting badly to damp....

You could always physically close the fuel pump relay and check if it will then start.

When my original fuel pump relay failed (long ago), I took it apart - it was full of water!

I'm amazed it ever worked.

[Barkychoc]

Never mind voltages do you have a good earth connection to the ECU?
I have a V8 so don't know if the V6 is the same but I have a load of earth wires bundled together onto one large terminal which bolts to the chassis tube just behind the passenger side wheel - what a great place for it!

Chris

[trevytrev]

Found the problem !!..

It was a dodgy earth connection to the master relay (which sits between the ignition and the ecu), I found my haynes "engine management and fuel injection systems" manual ! which has a load of information for testing the key components to the ECU, in there it has a section for voltages supplies to the ecu, basically I tested pins 37 and 57 on the ecu which should be live when the ignition is on. Both of these had no power on mine (which explained why I was not getting any fault codes from the ECU), so I simply traced the wires up to the master relay which I then duly by-passed and everything suddenly came to life.

Testing the relay connector showed the earth link was not working, replaced the connector to the earth and it's fine ...

Just need to tape everything up and put it all back together again !!

Thanks for all your help guys ...