999 running on one cylinder after about a minute of start up , Thought it was temp related so changed the plugs but no, tested the coils and both fine. Any ideas please? Thanks
One failed some time ago so replaced it with a used one - all fine for 200 miles or so , problem came back and I assumed, as they were probably made at the same time, they would fail, also roughly at the same time. Which is the best test for an intermittent fault ?
swapping them over? - quickest and simplest apart from plugging in spark plug and resting on cylinder head for visual check. Is it "front" cylinder that has dropped out?
Thanks Chris ! Swapping I can't imagine will make any difference .. Its not the coils or plugs so what next ?
Have you got fuel to failed cylinder? if you remove plug of that cylinder is it wet?/ fuel smell? also - not that i've ever owned 749/999 but you can look for a fault code on dashboard can't you?
as i'm sure you know, have another attempt at running for a few seconds and then remove spark plug immediately for above check.
Have I got this correct? You have swapped or tested all parts on the failed cylinder: Coil pack, plug, lead? Fault says with the cylinder? But you have not yet swapped the lead from the source of the working one with the non working one? If you do this and the fault does move then you know everything is good with both cylinders and ignition parts. 99% the problem will be the ECU. I had this on my ST4s (996 engine) and rent through the same process.
If you have done the coil swap and the fault does not change cylinders then the issue lies elsewhere. Do you have the coil sticks with or without the fly lead. If without, then check the loom cable to them for chaffing. Particularly where the front one passes by the radiator. Swap the injector/coil/pump relay for a new one. If these fail then it is possible that the coil driver is failing in the ECU.
No fault code , have the fly lead coils . Seems to me fault occurs when the heat level rises .. 40 degrees after about a minute
Another possibility is that it is fuel pump related. Check the wiring where it enters the bottom of the fuel pump for damage. There is also a multi-way connector to the fuel pump that joins close to the top of the vertical cylinder. The wiring here can get pinched between the tank and cylinder causing chaffing.
Avanti race parts sorted mine. Not sure if they offer diagnostics. Whereabouts in the country are you?
Before you part with money suggest you chat to them, or whatever supplier you choose, to describe your symptoms. They may offer diagnostics I'm not sure. I know they will map standard or to suit exhaust mods etc
