10 minutes ago, alanrichey said:

Sorry to sound like a broken record but to me everything still points to a very weak spark.   As Ian said, a pushstart would prove it one way or another. 

I'm afraid Andy and I have run out of ideas.   You will probably have to get your breakdown service to take it to a local garage and let them try.

Appreciate the advice. 

my problem with the electric theory is we’ve tried very powerful batteries and engine jumps and it doesn’t explain the cutting out original problem. 
 

I did try breakdown cover but apparently I have to nominate the garage to take it to within 20 miles and I rang 4 and all were not interested in looking at a kit car. 

Has a slow starter been eliminated, are you able to tow start it, or at least attempt to tow start in 3rd? 

6 minutes ago, wazcov said:

my problem with the electric theory is we’ve tried very powerful batteries and engine jumps and it doesn’t explain the cutting out original problem. 

You might find that has been cured by the new TPS and fuel pump.   I appreciate what you have done but, for example, if the starter connection to the battery is corroded or loose or there is a poor earth somewhere then it won't matter how much power you apply it won't allow enough power for both starter and coil.   You need to get some burly mates to give you a push 😀   If that doesn't start it then it would have to be the ECU.   I have to say we have never seen an ECU fault in any other Superspec but I guess there has to be a first.

Can you post a video of the engine cranking again so we can check the speed ?

 I will try and film it starting. It turns over extremely quickly when jumped but my battery only gives a couple of attempts before it runs out

Edited March 16, 20251 yr by wazcov
duplicate

I have checked the coil voltages. It shows +12v at live and +12v at negative, which I've read is normal because the ECU pulling it down to ground at pulses is too fast for the multimeter to read.

I have also used a friend's compression tester to confirm all the cylinders are within spec.

 

Quote

Has a slow starter been eliminated, are you able to tow start it, or at least attempt to tow start in 3rd? 

towing is a bit difficult where I am on a residential estate with it garaged. On a jump the starter turns extremely quickly, and while not amazing on my battery it does well enough

Edited March 16, 20251 yr by wazcov

OK, it looks like we will have to run my analysis software again.   I;m seeing Andy this week so I will lend him my laptop and cable and he can gice it a try.

Any idea what this green and green/pink wire might be? Green was complete disconnected. Seems to go to a multiplug which sits on a small bracket near injectors (but not in)

Update: apparently just brake lights. 

Edited March 18, 20251 yr by wazcov

Is it a ballast resistor?

FIXED! Finally!

So it looks like the problem was that the previous owner had wired some cable from the battery 12v directly to a switch and then to a 'IGN Supply' (appears to be ignition supply) cable which then goes to the starter button. I took this odd cable off and what do you know, it cranks twice as fast and after a bit of spluttering from unburnt fuel it kicked straight into life.

The other problem of the revving and it cutting out also is now fixed, which I can presume to be the replacement Throttle Position Sensor (and/or the Fuel Pump).

Thanks to everyone for your advice and ideas, especially Al and Andy for coming by and helping out.

Good news, well done.   I can safely say I would never have figured that out.   Now we just need to find out why he did it 😀  (and fix your lambdas sensor heater)

Great work, well done. I presume it was a DIY security feature intended to isolate the ignition?

4 minutes ago, Jonty Wild said:

Great work, well done. I presume it was a DIY security feature intended to isolate the ignition?

I guess that was the intention but was just done plainly incorrect. No idea how it ever worked before tbh, maybe the cold winter weather was just harder to start than in the summer