I still can't find the problem with my car not starting. I can't think if a time when it has made me feel so unhappy having spent night after night trying to trace the issue with no problems found.... Today I am taking the ECu to a bike shop for them to try in a bike. This will be a double edged sword as if they find the ECU is broken, I don't know why, and if I find it is not broken, then I have no idea what else could be causing the issue....

With this in mind, I suspect it will be cheaper to pay someone to rip out the old loom, and rewire it all (the engine loom is a separate loom to the rest of the loom). If I sourced a replacement bike look to start with, how much do you think i would cost to have someone rewire it? I suspect a professional could have it done within a day - do you think that is about right?

Evening,

Had the same problem with my Zx10. Turned out to be two connectors I had crossed by accident. One was brown and the other Grey. Oddly they both could be connected into each other and once mated it was very hard to see the different colours.

Sorry if this was of no help, hope it works itself out.

Would you want to start from scratch with the whole car or just fit a new bike loom?

If it's fit a new bike loom to the existing loom we could do it in a day quite easily I would have thought.

Saves shelling out for someone to do it for you.

Ian - I am happy to pay for your time as I want the reliability and assurance of a professional install to avoid such problems in the future!

If you haven't found the cause and don't know for sure the loom is the problem do you really want/need to change it?

I'd advise finding the actual cause of the non-start first rather than applying a "parts darts" approach and just randomly throwing bits at it hoping to hit the cure. Can you not find someone local to come and have a look? A fresh pair of eyes often helps.

Or give us some symptoms and see if we can point you in the right direction....
Were there any problems with it prior to it not starting?
Had you altered anything or done ant maintenance that could effect it?
Does the engine turn?
Has it got sparks?
Is there fuel supply?
Is there compression?

Tim, I wont want paying.

I also agree with Adithorp, there is a reason the fault is there and that needs tracking down.

If the ecu is blown it will be hard to do a lot of the tests required to find a fault, but we can strip the loom and check for cable damage from over heating and insulation break down, and do all other tests possible.

Hi gents,

I did already try seeking help and more help from the great LCB massive, but so far I still don't have any solutions identified...

You are probably right that I can start looking again from the beginning once I find out about the state of the ECU from the local bike shop. It could feasibly be a fault in a circuit that isn't actually within the bike loom, but so far none of my tests have enabled me to find the fault. I have found a few odd results along the way (my clocks allow continuity between the ignition fuse and earth, the security over ride resistor only drops the voltage by about 0.3V at the ECU when tested with a multimeter etc etc etc.)

To answer some of your questions:

- No spark
- Fuel pump relay is not being triggered by the ECU, but all voltages appear normal at the relay
- I have had one issue in 18 months of running this lump, and that was when the main earth cable came out of the crimp, so non-starter
- It turns over just fine
- I had done no maintenance or alterations in the weeks before the fault
- Two fuses (ECU and Ignition circuits) blew about 3 minutes after starting it on the way home from a run out
- The two fuses were replaced at the side of the road, and the car fired up and ran for about 10 seconds, before stopping
- The fuses were not blown, but the fuel pump was no longer priming (this was the only symptom I could gleam at the side of a dark road)

So I can't figure out what to test next. I was expecting to find something obvious (melted wire, worn through insulation, failed connector etc.), but so far nothing... I have not fully stripped down the loom, as it is separated into the car loom (lights, horn, fan etc.) and the bike loom. These two looms are then bundled together. I have released the bike loom to trace what is going on, but I have not undone the rest of the loom, as I didn't think this was causing the issue - I might have to do so when I get back from being in China for the next 2 weeks!

Thanks for the help chaps - much appreciated.

I had a similar problem with a 2001 zx12 that i builded for someone else.

we searched around everything, around the loom but no problems there,

In the end it was the fuse box.. it has a relais and a few diodes inside that is giving earth to the ecu and the ecu gives the fuelpump etc free to run.

The relais and diodes gets triggered by the sidestand, clutchswitch and neutral switch.

I hope you find the problem, like someone else said already the ecu is pretty bulletproof.

Good luck Daniel

If it ran for 10 seconds after the fuel pump and ecu fuse were replaced, sounds like you have a running car. It was just running on the residual fuel pressure in the fuel rail. Have you tried hard wiring the fuel pump to see if it will start and run then?

I have not tried hard wiring the fuel pump and starting, but I have hard wired the fuel pump (relay) and the fuel pump worked just fine. My worry with trying to hard wire it and start it is that the ECU monitors the voltage feed to the fuel pump and injectors (same power feed) and flags any discrepancy as a fault.... I don't think the engine would fire, as I am not getting a spark (tested last week). Also when I did bypass the fuel relay, the engine did not fire up afterwards (on the residual fuel pressure).

@Daniel - I am 99% sure I removed the diodes along with that part of the fuse box. I already had a fuse box, so I wired the loom into that fuse box. As for the diodes, they channel all of the interlocks together to feed a signal back to the ECU. I have simply connected each interlock to earth as required (apart from the tip sensor which I glued to always run)... I will double check my loom to be certain that I took those out just in case!

I see you checked out the fuel pump relay, but what about the Ecu relay?
iirc (it's been years since i last touched a kitcar) with out that your fuel pump relay won't work anyway.

I have checked that the ECU relay energises when switched on (audible click), and the ECU is seeing 12V as far as I can tell (there is 12V at the connector to the ECU). I have also checked all of the ECU grounds for continuity, and they all seem to be present and correct. I want to be able to confirm that the ECU is switching on/powering up, but I don't really know how I can check that....