Dying in the Heat

[s.unsworth]

Went out in Type 3 Auto Variant yesterday. It was even Hot here in Cumbria. All running nicely as usual. After about 25 Miles the Engine kept dying out and struggled to Start again. It was very Hot in the Engine Compartment. Let it Cool down a bit. Started again but kept dying out after only a few yards, especially if I tried to give it a bit more Throttle. Limped home dying out and starting again. By the time I got back home to put it in the Garage all seemed fine again. What is it Type 3 with Twin Carburettors do not like about the Heat ? Usually Starts and Runs well from Cold ? Does not like to Start again when Hot after a Run.

Steve

[937carrera]

Have a look here: viewtopic.php?f=4&t=15204&start=25

Seems like it could be similar heat soak issues, do you have the insulating spacers in place?

If the engine is running hot, then I suggest you check all the cooling for leaks, or full movement of the thermostat & ignition timing.

I would also check that there is no blockage in the carb jets

As you know, you don't want an aircooled engine with cooling issues on a warm summers day. When new of course, they ran OK is the USA, much warmer climate

[broady_6]

As David says, sounds more like an overheating issue. I used mine on thursday and friday, it started fine and did motorway runs in the 30 degree heat with out issue. And restarted fine. Are you running super unleaded?

[s.unsworth]

Yes. I only ever use Super Unleaded. Started and ran no problem today but not been out for a drive. I`m wondering if I need to keep the Tank more Full of Petrol ?

Also just realised I have not got the White Plastic Cover that was originally on Type 3 Mechanical Fuel Pumps. I`ve always assumed that was some sort of a Heat Shield ?

Steve

[broady_6]

I think you should check the engine over, make sure the timing is correct, make sure the thermostat and flaps are free and working. Make sure all the tinware is present and seated. I cant see that tiny bit of plastic making much differece. Ive used cars with out it no problem. It definately sounds like your engine is getting too hot, rather than a fuel issue.

All the wheels free? a dragging brake will cause over heating too. It cost my friend an engine.

[Rhysos]

Snap! Yep, you are describing exactly what I’ve been experiencing lately. Although the causes may be different, the outcome is the same; car runs well, gets hot and then will restart until fully cooled off. David has already linked to my thread above, which details my struggles. In my case, I believe it was (is) a combination of things, but here is a summary which might give you some ideas to check for:

vacuum leak – intake manifold was not bolted firmly to the head. This was causing the engine to run lean and hot.
condenser – I had replaced for a new one, but it failed quick and made restarting really difficult.
timing – I had too much advance. Backed the timing off slightly, checked with strobe and now seems to be in a better place.

Also, as you are running a mechanical fuel pump, check that you are not experiencing vapour lock when the engine is hot. Peter suggested a good workaround for this, which is to cool of the pump with cold water when you experience this problem. Seems like that would also be a quick way to confirm or eliminate that as the cause of your troubles.

I hope you get it sorted, I am sure you will. Keep us updated.

[s.unsworth]

Apart from the difficulty starting when hot, all was fine until that drive out on Friday when the weather was hot. I believe the Timing and Vacuum Hoses are all O.K. They have to be on an Automatic for it to Tickover in gear then take up the drive without stalling when setting off. That did used to be really bad until I got a New Genuine Bosch Dual Vacuum Unit and fitted that.

I thought Air Cooled Engine Thermostats failed safe ? I have previously checked the ends of the Shaft that can be seen outside the Fan Housing do alter position from Cold to Hot.

Steve

[purplepeter]

Yes, they fail in the open position, provided that it's the old/original "Bellows" type of thermostat, the spring is fitted to the flap & there's no restrictive corrosion on the flap shaft.
Rhys doesn't have the flaps fitted if he reads this!

[Rhysos]

Well spotted, Peter! Yeah, my car doesn't have the thermostat and linkage rods fitted - another thing that has vanished over the years. I'm not sure if the internal flaps are still present, but I did recently check that they were not jammed in the 'closed' position (if indeed they are there at all) by using a curved piece of wire to carefully probe the area (used the end of the fan shroud as my access point). Thankfully the wire passed right through the area where they should be, so I know I am at least getting the full effect of cooling air from the fan passing over the heads.

[purplepeter]

Your flaps simply aren't there Rhys!
The tell tale is that you were able to remove the dissy clamp, without posting "How the flip do I adjust the timing"- Flaps are mounted on a cross shaft that obscures the dissy clamp nut, so you need a very thin 10mm spanner to adjust
Running with no flaps is fine, if the car is kept in a garage, but you might have problems over winter/ when parked up at shows

[Rhysos]

Well, that explains it. I have very good access to the 10mm dizzy adjustment nut and now I know why

Steve - have you managed to resolve your issue yet? I thought I had sorted the problem of my hot restarts, but went out for a drive the other evening and still seem to be having a similar problem to what you are describing

[s.unsworth]

Sorry but no. Not been out in the Type 3 again. It is back to starting and running fine from cold in the garage at home though. Going to Scotland in the morning for a week, so it will not get looked at until after that.

Steve

[Rhysos]

No worries. I’m also away currently on holiday, so the unresolved overheating issue at my end will have to wait also.

[Superunleaded]

Setting the timing may help.
In cold weather it can tolerate more advance.
Hot weather may be not.
Distributor wear especially electronic may cause unexpected issues.
Only a guess.
Leaking flooding carbs due to the float needles? Bubbling hot fuel in carb bowl overflowing?