Cold / Damp starting

[nickd01]

My 450 starts like a champ every time when it's warm and dry; never failed. It also starts like a dream if it's been sitting during the week being rained on e.t.c so I figure it starts well in the wet.

But, last weekend in Wales where it got very cold and damp overnight whilst it started in the morning boy was it rough. Wouldn't idle well, blipping the accelerator didn't make it rev properly, and it cut out and then struggled to re-start. Got it re-started, and then managed to hold it at 1500 rpm and it settled down. It did the same the next day as well. Back in London, it was damp overnight and cold - it did start in the morning but not very smoothly.

Does anyone know why it seems unhappy in the damp / cold combination?

[jonathant]

I find that I need to leave mine idling for a minute before the (presumably) fuelling sorts itself out. I can hear the revs drop slightly when it's ready.

[GreenV8S]

Depends where you have parked it, but if you park on damp ground the heat from the engine will evaporate water from the ground and it will then condense on the inside of the engine bay when it cools down. Totally different from just being rained on after it has cooled down.

[nickd01]

The problem only occurs from properly cold - i.e overnight. Never once it's warmed up and running happily.

[poorpeet]

As Peter says it is likely to be the damp thats causing the problem. If I were you I'd remove the distributor cap & make sure its bone dry inside. You can get condensation inside the cap & it causes tracking. Clean the outside of the cap & the leads to get rid of any surface dirt. I use a kitchen roll sprayed with WD40. Put in all back & take the car out for a run to get if warmed up. This will ensure that everything is nice & dry. Then once it has cooled down but before it is stone cold spray the ignition leads and distributor with WD40 or similar. This will form a barrier to the damp.
Important to do this in the order above or you can seal the damp in.

[GreenV8S]

As above, but I'd emphasise that WD40 is your friend if you have any damp starting troubles. It's often used as penetrating/easing oil etc but its intended use is to disperse and repell water, and it's very good at it. Even if you aren't in a position to clean everything inside and out, a generous dose of WD40 over everything can work wonders. Just be aware that it will leave a tacky residue which will pick up dirt (which can eventually cause further problems of its own) so don't use it just for the sake of it, but if you have damp starting problems it can be a great help.