Ignition system wiring diagram

[mikethebike1127]

Desperately required...can anyone help??? Cheers in advance.

Mike

[malc350]

Mike, is it not on here (maybe scroll to bottom: AJP loom)

http://www.thetvrsite.com/wiring-diagrams/9-wiring...

Malc

[JensenA]

No it's not I've been round to Mike's. What he needs is an diagram of the actual ignition circuit.
We've checked everything on the car thgat is obvious, even switched over the Ignition Control box in the boot, and the 2 ignition/fuel related relays. The car is just not sparking.
I'm pulling my hair out and it's not even my car!
Anyone have an idea what would stop a spark??
Everything obvious has been checked - plug leads, fuses, connectors, relays etc etc.
The only odd thing that is happening is that the fans come, and keep cycling on and off on as soon as the ignition is on - is this a clue to anyone?

[Steve_T]

Worth trying an ECU swap?

[gcpeters]

water in the ecu / main circuit board at the back?

GP

[Tanguero]

I would stick an oscilloscope on the injector signal pins of the ECU and see what is happening when you crank the engine.

If my reading of the diagram at http://www.thetvrsite.com/files/wiring-diagrams/bo... is correct you want the following pins

Odd Bank +12v pin 5
Even Bank +12v pin 29

Injector Earth signals
Cylinder Pin
1 + 7 1
2 + 8 30
3 + 5 9
4 + 6 33


Obviously I meant to say the ignition pins...
1 + 7 40
2 + 8 20
3 + 5 55
4 + 6 19

Edited by Tanguero on Monday 22 February 22:17

[headcase]

Any use?



You can make that bigger by right clicking, copy image location then pasting into a new tab

Looks like the injectors fire 4 at a time and the ignition fires 2 at a time (wasted spark), you will find there is a + supply to the coil packs and the ECU earths the relevent windings to create the spark.
I suppose it makes sense looking for the +12v on the coil packs first. Im no expert on cerbs but have lots of fiddling on other cars electrics under my belt

Edited by headcase on Monday 22 February 18:05

[Byker28i]

I've got one. Part of the stuff I squirrelled away...


hows this?

(link for big) http://www.pbase.com/byker28i/image/122205803/orig...

Edited by Byker28i on Monday 22 February 21:12

[mikethebike1127]

Thanks for all the replies guys. Managed to get everything checked out with the info supplied.

PS Thanks for the phone call Alan J. Great help (again).

[FarmyardPants]

You could check your earths - engine to chassis and chassis to battery -ve.

[ro_butler]

Ok, I am guessing that the 19-way connector mentioned below is not the 'big plug' that connects directly to the ECU? I am also guessing that the diagram in Headcases post shows the pinout for this 'big plug' (on the left of the diagram)?

If this is the case how do you identify pin number 1 on this plug?

The background is that I want to install a fan override switch and I think I can do this by pulling the 2 fan output pins to ground (which should flip the fan relays).

Anyone else done this? mikesr or Julian64, do you know if this will work?
I have a spare ECU in case it goes pear shaped

[Steve_T]

You indeed can bring the fans in by grounding the relays. Pin 1 is usually labelled on mutli pin connectors, but it's often a very small label. I can't remember if the ECU or the loom-side connector is labelled on the Cerb though.

[nelly1]

[malc_grn]

out of interest where can I locate the 19 way plug? is it in the engine bay or behind the dash somewhere?

[mikesr]

The 19 way is above the passengers knees. Take off the trim panel and have a dig around.

ro butler, have you had the mod done to the ECU to bring the fans in at lower temps?
It works a treat even sat in traffic as it cycles the fans on and off more frequently so I've never bothered with an override switch.

Edited by mikesr on Monday 15th March 00:19