Cold Starting Problems

[gingerwinky]

So, since the weather started getting colder in May, the wagon has become increasingly difficult to start, when I first bought him I would pull the choke out halfway, turn the starter motor and after 5 to 10 seconds he would start.

Since every night recently has been below zero or close to, it can take up to 2 minutes to get him to start, I would pull the choke out, turn the starter motor. If he didn’t fire then I would turn him off, close the choke a little, turn the starter motor and continue this until he fired. The warmer the morning the easier he is to start, one morning I had to open the bonnet and leave him for an hour so the morning sun could warm him up.

Once he is started he will fire up every time after that throughout the day, wether I drive 20 kilometres or 3.

Up to last weekend this is what had been done to the engine:-
Restrictor plates removed, tubular exhaust manifolds fitted, military alternator removed and replaced with a much smaller civilian one, military ignition system replaced with a standard land rover efi distributor and coil with necessary 24v to 12v converter.

A friend and I spent 2 odd hours tuning him, we stripped the carbs, cleaned the throttle valves and replaced the diapraghms even though they were serviceable. Whilst balancing the carbs we found that the rh throttle was fully shut at idle, the throttle linkages were all adjusted and the fuelling set.

Before we tuned him the wagon pulled cleanly, didn’t hunt, we were quite surprised at how far out the tuning was to tell the truth.

Yesterday morning we checked the fuel pressure, both pumps were pushing out a steady 2.6 p.s.i.

By half 10 it was warm enough to be in t-shirts, it took 3 adjustments of the choke position for him to start.

I had a closer look at the lh carb, the extreme cold weather adjuster is damaged and it looks like someone has been into the choke housing previously.

Has anyone come across a fault like this before?

A big thanks for any comments.
Andy

[disco2hse]

Poor starting can be any of the things you have addressed. It may also be spark leakage (new HT cables required),
fouled or burned plugs (replace all the plugs),
plugs are too cold (get hotter plugs),
poor fuel quality (use 95, minimum),
blown head gasket or cracked head (get pressure check or look for oil/water in the cylinder),
burned or poorly seating valves
insufficient vacuum (not sure if your EFI uses vacuum pipe but if there is an air leak),
float chamber fuel level too low,
choke butterfly not fully closing,
carburetter throttle prop lever jammed open.

[gingerwinky]

Hi Alan,

Thanks for the speedy and as usual, very informative reply.

Two things jump out at me straight away, you are the second person today to tell me I should be running the engine on 95 RON fuel and not 91.

When I bought him in March I did a full service and replaced the leads and spark plugs, because of where I bought the plugs from I just assumed I had been given a superseded plug but having gone onto the NGK website I do have the wrong plugs fitted. I should have BPR5ES fitted but have BPR6ES fitted which is a colder plug.

Also, the website mentions an upgraded plug, BPR5EIX. Do you have any experience with this number or should I just stick with the normal part number?

Again, thanks for your reply.
Andy

[disco2hse]

Certainly 95/98 is the way to go. The engine needs to be tuned for it too. With lower octane, you are likely to get pinking because the spark is advanced for higher octane fuel. Easy test is to run our all the fuel in one of your tanks and fill it up with high octane

Yes, you need the hotter plugs and 5 is the minimum. I have also used 4's when I was having some issues with mine starting due to worn cam shafts and lifters.

For the BPR5EIX, these are a high performance plug. Functionally, there should be no difference given you are running a low compression, low performance engine. Difference will only be in the price for you.