No Spark.... Help (C1J)

[Ashy]

Right Gents, need some help here...

I've got myself another 5 but is has a few issues, it was basicaly bought as spares or repairs with the idea of making a track car. Anyway we've spent a bit of time on it today and made some good progress.

The car had loads of random imobilisers and dodgy wiring which was removed straight away to try and get back to basics. We've now got the engine turning over but the fuel pump doesnt run (not sure if it does until it fires up?). Also got no spark on the main king lead.

So, I've checked all the main lives and switch lives behind the ash tray, all OK. Also checked the AEI relay in the scuttle tray and I've got +12v on the switch lives and I've got 12v on the switch live into the AEI

Tried a known good relay and king lead and no joy... I also checked the resistance of the crank sensor and it matched the resistance of a known good sensor (not sure if that means its OK tho).

So what else can I check?? I'm all out of ideas

On a positive note it has a full tilt and slide electric sunroof which I managed to get working, its mint, really smooth and a little flap pops up at the front as it opens

[Kris M]

fuel pump will only run once the engine is turning over. Take the fuel pump relay out behind fusebox and bridge the white and red wires, the pump should them run continously, eliminating the relay etc

Try another working AEI maybe ??

[Brigsy]

Possibly tdc mate, swap it for a gooden.

[Spooky]

Fuel pump will prime when the ignition is turned...it'll whine for a couple of seconds after you've cranked aswell.

I was going to suggest the fuel pump relay/tdc lead etc but you've checked that...

Try another AEI maybe...

[Scoff]

Check that the earth to the AEI is good too. no point in having 12v on the live if you don't have 0v on the earth

Is fuel pump kicking up when you crank ? If it is, it would suggest AEI is alive, so maybe the AEI has a problem in the HT side - next test would be a replacement module. If there's no fuel pump then definately a power supply, ground or TDC thing.

[Spooky]

If there's no fuel pump then definately a power supply, ground or TDC thing.

Ditto

[Mart]

No spark on the king lead (assuming it's not open cct) can only mean a lack of 12v and/or good earth at the aei, failed coilpack/ht coil within, or dodgy tdc sensor.

If you've got 12v & ground at the aei input, stick a 12v bulb across the coil +/- terminals, crank the engine, and see if the bulb flashes. If it does, the coilpack must be shot. If it doesn't, either the aei itself is goosed, or that tdc sensor isn't as good as you thought.

The fuel pump won't run (relay energised) if the aei isn't seeing a good tdc sensor signal.

I take it there's a flywheel in situ?!

[Ashy]

Yeah I bridged the Fuel Pump Relay and the pump ran so no problem there.... Does the AEI need to be ground to the car body through the bracket its mounted to as mine wasn't?

Right so need to check the earth on the same plug as the switch live and also maybe change the tdc cable? if all else fails try a known good AEI?

[Spooky]

Sounds like a plan

[Nick k]

Fuel pump will prime when the ignition is turned...it'll whine for a couple of seconds after you've cranked aswell.

I was going to suggest the fuel pump relay/tdc lead etc but you've checked that...

Try another AEI maybe...

Wrong!! its not EFI, Fuel pump does'nt do that.

3 pins plug on AEI.

Yellow +12v
Black 0v
Pink = to fuel pump relay under dash.

Fuel pump will not run until the crank signal is seen by AEI and outputs a signal on pink to fuel pump relay.

[Spooky]

Evidently...I'd argue I'm right...my wording however...

Is 'When you turn the ignition key to START the engine, the pump will prime...' any better ?

[Nick k]

Evidently...I'd argue I'm right...my wording however...

Is 'When you turn the ignition key to START the engine, the pump will prime...' any better ?

I would say the pump will run and pressure the fuel circuit to the carb!!! To "prime" would indicate its only going to run for 2 secs or so I'll give you 7/10 for trying.

[Spooky]

Technically the pump isn't 'running' until the engine fires up, the engine is turning and the pump is maintaining the fuel pressure upto the carb...it's 'priming' the fuel circuit upto the carb...that's what I see as priming...does that make sense?

[Nick k]

Ahhhh wrong!! The pump will run as soon as a rpm signal is seen by the AEI either if its cranking or the engine has fired and is running, so they can be classed as the same thing!!

Anyway, bored now with this basic problem

[Spooky]

Of course of course

[Nick k]

Nice thread hijack!! Lets hope there's enough info there to sort the original fault out!

[James5]

Nial,
If you have no spark there will be no signal to Fuel Pump Relay as peeps have said above it can only be a one of a few things,

TDC lead
TDC connection to AEI,
AEI Relay,
AEI itself,
AEI Earth,
Connection damaged when immobiliser wires removed could be an idea to give the AEI a new earth, live feed straight from battery to eliminate some of the wiring routes.

I hate wiring

[Ashy]

Sorted, had a play with the sl@g today, just needed an earth to the AEI, you learn something new everyday. Fired straight up after years of not moving... Runs sweet so well happy

Cheers for the help.

[dave j gtt]

pictures ?