Hi All,
I don't have the car yet, its being delivered at the end of the month but prior to getting the vehicle I have some questions I would like to ask:-

1) The Starter Solenoid has a black wire floating around doing nothing, the previous owner has another black wire going from the top spade connector into the cab area, any ideas what the 6.3mm spade tag is for? is it solenoid enable or it is power feed to the coil whilst cranking? maybe he has bypassed the inhibitor on the gearbox?

2) The distributor, I took the cap off as it wouldn't start, the points were permanently closed, minimal adjustment, wondered if the plastic tab had worn down or wrong points fitted? so considering converting to an electronic ignition module inside the distributor, any thoughts on this or should I just buy a new set of points and condenser and coil and put them on as it should be?

3) The Oil Pressure gauge in the car didn't move at all, plenty of oil in the engine but when it was trying to start, it got to 300RPM on about 2 cylinders and no oil pressure. is the gauge electric and possibly a faulty sensor/supply or capillary and I have a problem?

4) The Gearbox inhibitor, if you are not in park, does it cut power to the engine or to the starter solenoid?

5) Between the 2 carbs there is something with a wire on it which was spitting fuel back at me while we were trying to start it, is this some kid of electronic choke mechanism and how does the choke work?

That's enough for now, I will have more when I get the car and start digging around but doing research mainly prior to delivery.
cheers,
Spence

 

First welcome to the forum. Can you add you location in to your details so we know where you are.
Lots of others will pitch in here so starting with number 1.
The starter solenoid under the bonnet acts like a relay. You have a large wire going in from the battery and a large wire going out to the starter motor. You then have a small wire going to a terminal which comes from the dash starter button which is connected to the key. The principal is that the dash button will not work unless the key is on. The button on the solenoid will turn the engine over but will not let the engine start unless the key is on. The starter button operates the solenoid/relay so power can go to the starter motor. The key allows power to go to the coil so the car will start.
Number 2
I would go for an electronic distributor. There are several on the market. I run a Stealth distributor from Accuspark on my S type. AccuSpark Electronic Ignition Never had a problem with it but they are earth sensitive so I had a positive earth system on my car then had to buy a new one when I change to negative earth a couple of years later.
Number 3.
The oil pressure gauge is electric on my S type and I assume it is the same on the 340 as they were built around the same time 1968. Although they are not that accurate they do work and give a reading when connected. The sensor is fitted on the top of the oil filter housing. It is just a single wire on a round screw in sensor. I personally would not try and start the engine unless I had a working oil pressure gauge. With the plugs out you should be able to spin the engine over on the starter motor and the gauge should show 30 psi minimum. Oil in the sump does not mean oil is being pumped around to the bearing.Some have converted to a capillary type oil pressure gauge but I have not needed to.
Number 4.
The inhibitor switch on your car being a 340 Auto should be on the side of the gearbox as you should have the BW35 auto box. Previous cars prior to 1967 ran the DG250 gearbox and the inhibitor was under the dash. All the inhibitor switch does is stops power going from the key to the dash starter button and the solenoid button if the car is in reverse or drive. If you look at the wiring a wire goes from the key to the inhibitor switch and then back up to the dash starter button. If the car is in drive or reverse it just breaks this circuit so the button does not work but going back to the solenoid under the dash if the key is on and the gearbox is in drive or reverse the button on the solenoid can start the car whilst it is in gear if the wiring has been messed with.
Number 5.
The thing between the carbs is called the Automatic Enrichment Device or AED for short and it acts like a choke. There is a solenoid attached to a needle and when the AED is activated the needle lifts and allows extra fuel and air into the engine. The AED works on a bimetal switch called the Otter switch and if you search this on the forum you wil have to spend three days reading about it. Basically it works on engine temperature. When the engine is cold the bimetal switch creates an earth which allows the AEDs solenoid to lift the needle. When the engine gets to approx 35 degrees C the bimetal switch opens and the AED solenoid looses power and closes. The Otter switch can be temperamental not creating a closed earth so not working, opening and cutting off power to the solenoid to early so the engine stalls as it has not choke or fails to open so the AED is permanently on which is not good for the environment. A lot of us including me have set up a manual switch so we can control the AED via a switch under the dash by passing the Otter switch.

I am sure others will give you even more information. Don't be afraid to ask questions as we all enjoy trying to help out. Adding photos also helps us to identify parts if you do not know what they are or what they do.

 

Hi, OK, I did an intro but never put it in my signature... oops...
I am based in Gloucestershire in the UK...

ok so reading between the lines, the spare wire going to the solenoid I reckon is a spare power feed as the engine was cranking in park and even when it slipped into reverse so my guess is the inhibitor has failed and he has bypassed this. Thats fine, I can fix that. I will order a new oil pressure sensor in case it has failed, I did see that when I was looking under the carbs.
makes sense on the choke replacement system, that seemed to be working.
I will have a look at the electronic ignition when I get the car delivered as the seller said he would get it running before hand anyway.

Thanks for the great feedback, gathering information slowly for the rebuild so i know what to budget for.

 

53Buick: Although for a later model, this video explains how the AED functions:

 

the AED is also known as an electronic choke or Cold Start Enrichment Device. It is known to spit on our faces when one gets too close. It is also known in the USA as Sir William Lyons Curse. He had the last word on the MK2, S type, 420, and XJ Small Saloon designs.

You should be able to START the engine in PARK and in NEUTRAL, but not in any other shifter position. If you can start the engine in Reverse or any other shifter position, something is wrong with the Neutral Safety Switch, as known in the USA.
It might be out of adjustment or wiring connected incorrectly as the Factory Service Manual has a documented error in the Wiring Chart.
These switches rarely fail. so it is most likely one of the latter.

 

The enrichment device is also known as the 'hisser' because of the noise it makes sucking air when it's working. Although it has many AKAs, it's not a total criminal and, when properly adjusted, works very well.

 

If you're on the eastern side of Gloucestershire, you might like to participate in the Oxfordshire area of the JEC. It's a very active group with some expertise in 1960s cars.

 

Welcome:

 

Ok, thank you very much for the replies and sorry for not confirming any yet but I have been on holiday.

So, great news, the car is here! all paid for and delivered.
I have given it a full once over and can confirm the gearbox inhibitor is broken and the black wire is just bypassing this. I will be replacing this.
The points have been replaced and now it starts, sometimes it sounds amazing, sometimes like its missing but 5 gallons of new fuel helped.
Electrics are in a bad way, the car has lived on the UK South coast all its life and it shows.. I am getting electrics work one minute and fail the next so I will be going through everything with WD40 and contact cleaner.
When checking the non functioning horns out I noticed some bad rot at the front, crossmember, Crows feet etc.... that will be a nice job for the winter!
The dash, the top of the dash is in a bad way as is the left hand wooden A pillar section. if anyone has a spare I can use and cover with black vinyl until I repair the veneer then please let me know.
The gauges dont work, I think this could be down to the electrical corrosion but also, the voltage stabilizer is stock and the car may have been converted to negative earth so I have ordered a new V-reg and V-Stabilizer and battery and let see what happens.
The tyres are shot as expected so I will be cleaning up the wires and looking for some nice white bead tyres (tubes I guess too).
The paint is flaking off the roof, bonnet and boot where its been restored before and the paint is very thin.

so it sounds like its a bit of a wreck but it is complete and I love it. I got it for a good price I think so I have room to invest and its a keeper so all is good.