Hi Guys, I hope all is well.
Sorry not to get back sooner - life is a massive juggling act at the mo, as I'm sure it's the same for everyone so no excuses hay.
Anyway, to recap the GTA Turbo would start, idle and drive OK when cold, as soon as the engine is warm/nears normal running temperature it coughs, splutters, eventually cuts out and won't restart. Leave it to cool down repeat the process.
So, the fuel pressure regulator tested OK, the temperature sensor tested OK, crank sensor OK. Using an R25 wiring diagram all inputs back to the ECU measured correctly, earth bonding/continuity correct.
With the engine still slightly warm we used a transparent spark plug tester on one of the cylinders (rear L/H cylinder, the number escapes me) and the spark, although present was weak in comparison with the glow when connected to the ignition module.
Anyway you can guess what's coming. Dizzy cap removed and contacts were green with corrosion, same for the rotor arm. The cap & arm are circa 18-24 months old and the moisture present was surprising - not dripping but noticeably present!
So the cap and arm were dried and cleaned, resistance of the rotor arm now 1Kohm and not 1Mohm! And yes the car fired up on the button, up to temperature, stop/started & drove as it should.
Ultimately it looks like that when on 'choke' from cold the excess fuel was compensating for the weak spark allowing the engine to run of sorts, when warm with lower fuel throughput the reduced fuel & weak spark was not enough to keep the engine running...
Sum-up:- An incredibly basic fault with an easy fix. Over thinking has cost a lot of time (and money) but also a great learning experience as far as I/O's from the ECU and expected measurements of the sensors etc.
But I must say a big thank you to the following:-
Johnc
Darren
Lee
Stephen Dell (thanks for telling me it won't be anything major)
Best regards,
Matthew.
