I bought mine a couple of years ago. Its a 2.6L petrol twin-cam v6. Picked her up a good few miles from home so thought I'd see how she felt. Thought she just slowed down a bit approaching 100MPH. Then there was a sudden shudder and the CEL came on. Stopped and felt the engine running rough in idle. Switched off and on and it was fine - CEL still on.

Called the seller. He said car was reporting a CPS error code so he had just had the CPS changed. So I should see how it behaves and if it happens again to let him have the car. CEL went off after a few ignition starts. A few days into it and the weather changed drastically. We had heavy frost and guess what? - the next day the car wouldn't start! Cranks fine, just no catching. Let her crank a few times and nothing would happen. Then, a few minutes later, crank and it would catch fine. CEL would come on, but otherwise car would perform fine. All day. No problems at all when hot.

Tried the 100MPH thing a couple of times and both times same as above. Note that the RPMs don't matter. I can easily rev up to 5k rpm in town on kick-down. Never a problem. The engine needs the added resistance offered at sustained speed.

By now I was so used to the cold start problem. Frost the night before (car is parked out on the drive) and current temperature between 3 - 6C and it would not catch. Of course, until it wanted to (every time exactly as above). If it was over 6C or it was below freezing, it would not have a problem starting cold.

Anyway, gave the seller the car. He said the CPS code was still there so he had the CPS changed again. Sorry but he couldn't remember the exact code number.

I did not have the starting problem after that.

It was next year (I go away for long periods) that I got her out onto the motorways again. Cruised at 120MPH for a good 40 miles, with speeding up to 130MPH. No problem.

All that year, no starting problem (through frost n all).

3 days ago, frost first time this winter, ... yep! cold cranking no start issue again.

Now, first time around, I had to come up to speed with info on the electronics on these engines. Couldn't have done this without these forums. PLUS, I have time on my hands - this is like a vacation car so not used much. I went through the Battery, MAF, plugs, petrol supply, ignition etc discussions but just couldn't see a problem here. And since the CPS change seemed to fix the issue that was the end of it.

SO - this time around, I think I will pursue it as a CPS issue, although not the sensor, but the connections. This does explain the frost-only reaction as frost, in the process of melting, may accentuate a bad connection or affect an exposed connector/ split insulation/etc. This, I think, would also explain the high speed issue since a bad connection can cause an ever-so-slightly mistimed CPS signal to distort enough at high revolutions, under load, to provide a mistimed spark trigger from the ECU.

3 days ago when the no start issue came up I didn't keep cranking. Instead I opened the bonnet and tried to reach for the cps connector. It was night and I don't think I reached it but did ruffle the wiring running in that area. Well, the next crank started the car!

2 further tries and it starts first crank (although the crank does go on for longer than normal). I think I'll check the wiring properly at the weekend.