940 LPT 2.3 problems starting in damp
 

My 940 has had problems this week starting up in damp weather (I'm assuming that damp is a factor as I've not had problems otherwise). I was advised to change the spark plugs, wires and distributor would resolve the issues, but two days later I've had the same problem.

The engine cranks but won't start and you can hear the engine misfiring slightly before failing to start. The recovery service earlier today managed to get it started by cleaning the ignition coil connections, after which the engine misfired for around a minute when starting before gradually getting going. The car runs well when hot and isn't stalling at all.

I was wondering about whether the ignition coil was part of the problem and whether there are any tests I can do to narrow the problem down? I have the car booked into another garage on Monday but I suspect that they'll not be able to find it. I had the oil breather box and hoses cleaned and few weeks ago so I'm wondering if this could also be related to that.

Just realised I hadn't asked any clear question so. Does the below sound like a good plan of attack?

- Replace ignition coil
- Fuel filter
- Crankcase position sensor
- Better spark plugs and leads (not currently OEM).
- Are there any good points to attack with contact cleaner to help with the starting in the general?

I don't really want to start replacing everything in the hope that I'll solve the issue, but not sure where to start currently. The battery should be good - I replaced it around a year and a half ago.

One thing to check is that the HT Lead is properly secured to the distributor cap, as it's in a really stupid place.

What plugs have you got at the moment and what are the gaps like on them?

Also worth adding, as suggested before i think, about 2L of meths to the fuel tank as long as it's at a 1/4 or below. Can't remember if you did it or not last time i suggested it.

Thanks Loki - I'll give that a check. I'm guessing it would worth replacing the HT lead from the ignition coil to the distributor? I don't think this was replacing alongside the other wires.

I've sent you a PM about the code reader by the way - I can't see the message in my sent folder though so let me know it does not come through :regular_smile:

New spark plugs were put in by a garage a few days ago, but I don't know what brand they were I'm afraid. I'll have a look.

I think you might have mentioned the meths to someone else laird :regular_smile: I currently have well over half a tank left - why do you need to make sure that the tank is 1/4 or below?

Do you have the old original plug leads?

It's all to do with the concentration of the meths, needs to be about 10% for best results. When there's about 1/4 tank left, that would in theory be 3 1/4 gallons. As there's usually about 1/2 - 1 gallon left when the gauge actually reads empty, 1/4 tank on the gauge is about 3 1/2 - 4 gallons.

Converting 4 gallons to litres works out at 18L so adding 2L of meths gives 2L in a total of 20L so is 10% concentration.

If it is condensation in the tank, since it's turned cold will make it worse as the condesnsation will form easier.

I might be wrong but from your description it sounds as if you have condensation in the tank. It settles overnight causing a poor cold start because the fuel pump is pulling the water from the bottom of the tank.

Once it's warmed up and has been moving, that condensation has not only been sloshed round the tank but the fuel returning from the engine that hasn't been used causes a swirl effect in the bottom of the tank where the pick up is for the pump.

This is a baffled area to minimise fuel starvation under cornering, acceleration, braking etc but also the lowest point of the tank on a flat road.

For the cost of 2L of meths from Toolstation (about £6), it's a cheap and easy thing to try. If it doesn't make any difference, it will remove any condensation that is starting to build preventing a future problem for a while in any case.
Also eliminates condensation as being the cause of the problem. :thumbs_up:

no misfiring under full load acceleration?

Can't believe no-ones suggested this yet but here we go...

Take the dizzy cap off, clean the inside and have a spray round the insides with WD40 :)

The next time the problem occurs try this process and if it works then you can be certain that water/moisture is getting into your dizzy cap and causing the issues.