1.8 won't start after Clutch replacement.

[Adamb585]

My 1.8 2002 Cabrio wont start after replacing clutch- So here goes:- 
Checked gearbox earths, Replaced ECU relay with one from wife's car, full volts present feeding all pins to relay, wired out the inertia switch, unwrapped loom and continuity checked all wires between relay and ECU, and earths for ECU. 
 No Battery light, all fuses here checked, and wires traced to alternator.
 Tried spare key and many various reset ECU/key procedures! cleaned the Flywheel sensor but was thinking of trying a new one.
 I have also changed spark plugs whilst doing the clutch, I have checked the connections and tried a spare coil pack I have.
 So I am assuming ECU could be locked by immobiliser circuit? If so can this be bypassed or do I need to source an 'unlocked ECU'
If you've got this far thanks for reading and I eagerly await any responses.
Cheers Adam.

[bashbarnard]

check that the starter motor is getting its 12v feed. that wouldve been the first thing i done! there should be a permanant on the big wire and a live on the other when the key is turned to start

[welshpug]

check the central locking fuse.

[Adamb585]

Sorry I should have said no issue there she is spinning over fine, I have even taken the inlet manifold of to clean and check all the connections.

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All fuses tested and central locking working.

[1616six]

Tried the old plugs? Long shot as I assume you've either not reconnected something or blown something but worth a look.

[andywhy]

Is it possible to put the HT leads on the wrong plugs when refitting? If so I'd double check they're right.

[welshpug]

no, its a wasted spark coil on plug if its 16v

[Dale]

Cut switch on the inner wing should have a red top! That's the usual culprit!
I might be wrong but it's the first thing I check!

[Adamb585]

Yes that was my first thought and the first thing I ripped out and bypassed! I have now had the ECU tested and unlocked, but now the fuel pump is still not working but is putting a short on to fuse 9 in the engine bay fuses, so am awaiting a second hand pump. I have voltage at sensors now and she tries to fire on easy start, but still no battery light? Not going to waste too much more time or money on it.

[markj]

Hi, New to the forum, so apologies in advance for any incorrect behaviour!

Have a 306 with similar problems. When I turn ignition the starter motor fires but car just will not start. Maybe because it's been sat for a while. Anyway, last time i did start her (2 weeks back), it took an age and I almost drained the battery. However, what I notices when turning the ignition on (not over), was there was no pump noise. Then after a very long time I heard the pump go on. It then fired up OK. So I thought I have a dodgy pump.
Hence why today I decided to strip the pump out and take a look. I applied 12v to the pump and shot fuel all over the place. Well at least the pump works. I refitted, but still no pump noise when turning ignition. Measured voltage at the Pump connector. There are 4 terminals 2 for the pump (+ve and ground), and 2 for the level indicator switch (+ve and ground). I only had 11v on one, all other terminals had zero. As the fuel level indicator is working I surmise that there is no +ve getting to the pump. Might be an idea to check this before buying a new pump! Checked fuses, not knowing which to look at, all looked ok. So think it's something else between pump and ignition. The found a thread about ECU and pump relays, but not much else. Any suggestions? Should I be posting this as a separate thread? Thanks.

[pug306driver]

I applied 12v to the pump and shot fuel all over the place. Well at least the pump works.

Petrol or diesel?? i assume diesel as you are still with us!

There is a brown double relay under the back of the ecu I think, ( still a tyro on these cars ) which controls the diesel lift pump in the tank.

There will be info on here but not sure where, just look at/read similar threads and have a note book handy.

Same for the petrol ???

Genny warning light, i think the alternator has an ecu feed, but not sure which terminal on the aternator it is, again read threads an have a note book handy.

[markj]

Shortly after my last post I managed to get the car started.  Don't ask me how.  The things I did were...
- Removed pump from car and put 12v on motor connectors - Pump worked OK.
- Found the ECU relay (Also referred to as: Fuel Relay, Engine Management Relay).  Mine is black and mounted on the back of the ECU housing.  It had a cracked housing and was loose.  took it off, opened the housing and assessed the contacts.  All looked ok. 
- Checked the Red topped button (Fuel cut-off; Inertia switch), near to the ECU relay.  Checks out fine. Switch closed OK.
 So after a lot of Bu&&ering about I turned the ignition into the 2nd position and I could hear the fuel pump prime for several seconds.  Engine fired up perfectly and ran for a couple of weeks.

Now....   I have been away for a couple of weeks and guess what?  Yes, the car won't start.  So, not knowing what I did last time, I repeated my efforts...
- Pump out and runs off 12v supply.
- Relay out (tapped)
- Cables wiggled a bit
- Checked the inertial switch
But, nothing has worked.

I joined good old Haynes and signed up for on-line manual, just to get the elec dwgs.  So now armed with a bit more info, I couid check the wiring supply voltage.  Well, it would appear that the relay for the pump is not closing, not supplying 12v from pin 8 to pin 5 of the relay.  Pin 5 then goes to the inertia switch which is where i could check for 12v (Nothing there).  So I removed the relay housing and witnessed the inactivity on the right-hand relay.  If I manually close the relay the pump will run, and if I over-ride the relay to be on, the pump runs and the car will fire up ok.  Not sure this is good for the car!  

So, the pump works, the inertia switch seems OK, but the relay is not closing.  Now, this is where things get a little vague.  The relay seems to have some other electronics, which I suspect turn the pump off, but not sure how or why.  This would normally be backed up by the pump stopping after initial priming before teh engine is tuned over.

My questions are...
1.  Is it a faulty relay?  - I have a new one due tomorrow, so will rule this in/out.
2.  What else controls the relay?  Seems that the additional electronics are wired back to the ECU.  
3.  Does anyone know or understand the control methodology of the ECU?  What would cause the control to cut-off fuel, turning the relay off?

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Sorry. Petrol 1.4i LX

[vincent1]

if that pin on the relay goes back to the ecu etc maybe its a immobilsor issue you maybe just bypassing it by closing the relay manualy im not sure if the immobilisor cuts just the fuel or the spark too trying a new relay will rule it out next step mi guess would be getting the immobiliser side of things checked out.