Austin wont start

[pendragon374]

Hi, folks, this is my first thread on the website after joining some months ago and need some help.
I have an Austin that I just cant get started with the correct firing order. I have read other articles on this but still stumped. The car was running fine until recently ,I replaced the fuel tank as the old one was rusty, new fuel lines and rebuilt the fuel pump and  carb. I took of the distributor and replaced it with a new electronic ignition unit . I also fitted a new wiring harness and exhaust whilst the car was in bits. What a good job......I thought. 

On trying to start the thing it would not run at all. I checked for leaks in the fuel system but none found and the pump was working well. Checked for leaks in the carb and manifold but nothing noted. Checked the electric side and there is 6 volts to the coil and a good spark at the plugs. The firing order was correct 1342 from the radiator end and correct on the cap running clockwise 1342. All in line with the flywheel 1/4 marking about 1 1/2 inches from TDC. Checked the compression ,all around 60 but would still not start. I took the electronic ignition off and replaced it with the old points system ,still nothing. Losing my patience I started to swap the leads around and found that the car started with the leads in reverse order (number 1 being next to the bulkhead ). The car ran but not very well. The revs were up and down and high even with the idle screw turned right out and sounded rough and unhappy, with the odd pop from the carb. I tried turning the distributer in all directions when the car was running but made only very slight improvements to the engine which stalled once you touched the throttle.
I have reverted back to the proper firing order ,taken the distributor out and turned it just about every degree around and replaced it but still nothing.
I am at a loss. Any ideas ?
John

[David Stepney]

I suspect that you have two problems, Pendragon.
1. There are no timing marks for setting the distributor on the gears, so, when timing the engine, you have to make sure that you have TDC No: 1 cylinder firing (i.e. both valves closed.) Set the points gap to 12 thou/inch and insert the distributor into the dynamo with the rotor arm pointing to No: 1's contact in the distributor cap. Remember that the distributor runs clockwise when setting the firing order., Once fitted, (and assuming that you have set the flywheel 1/4 mark to about 1 1/2 inches before TDC approaching from the right as you look at the flywheel) turn the distributor until the points are just opening (I use a test light to check this) and the rotor is still pointing to No:1 contact. Reconnect everything and it should start. If you had to reverse the leads to get it to run, then you distributor was probably 180 degrees out.

2. If it runs badly when you do get it to run as you describe, I would first check for any air leaks on the inlet side as a start.

[John Cornforth]

Hi John

I think David has hit the nail on the head, the timing is/was grossly out

Just to put things another way, when the flywheel 1/4 mark is at the top, it means that either Cylinder No 1 is firing OR Cylinder No 4. You can't tell which is which without some extra information.

One way is to look at the valves, where the firing cylinder will have both valves closed (springs uncompressed).

If it's too much of a faff to take off the valve chest cover, an alternative method is to take out the spark plugs and put your finger over the plug hole of No 1. You should feel the compression as TDC is approached. Unless you are a contortionist you will need an assistant (glamorous or otherwise) to turn the starting handle.

Although the plug lead MUST always be in the order 1,3,4,2 clockwise, you may find their angles don't correspond to the "book" positions because the distributor gear has been engaged at a random/incorrect angle. This doesn't affect engine performance so you can just leave them be, but if you prefer things to be "right" you will have to lift out the distributor, reposition the gear (you have 15 positions to choose from, i.e. steps of 24 degrees) and test again.

Good Luck

[Chris KC]

Is this a DK4A disributor with auto-advance? Then set it so the points just open (blue Rizla paper held between the points comes loose) at TDC. Worry about fine tuning when it runs.

Check it is rotating clockwise (when viewed from ABOVE - this is an anti-clockwise unit in Lucas designation). 

As David suggests, the best engine-killer I can think of if you have a spark and compression is an air leak at the inlet manifold - not always easy to detect so in the absence of other clues it may be worth extra attention.

Otherwise attached may prompt a thought.


  A7 Doesn't Start.xlsx (Size: 19.27 KB / Downloads: 22)

[Howard Wright]

Hi Pendragon

I found it difficult to feel the compression by placing my thumb on the spark plug hole.  So I use a compression tester without the dial gauge but the finger of a rubber glove fastened over the end.  As you crank the engine the glove finger inflates.  Do it too quickly and it pops like a balloon.  If you don’t have a compression tester, sacrifice a spark plug by drilling out the core.

Once you have established TDC on No 1 compression stroke put a dab of paint on the cam pulley immediately by the bolt on the dynamo housing.  In that way you will always be able to find TDC on No 1 without resorting to cutting up a rubber glove.

Cheers

Howard

[Graham Barker]

I have a simple way to find No1 firing position without the use of an assistant. Take out all spark plugs except No1. Crank over the engine with the crank handle until you feel compression developing. That will be No1 cylinder. Take out No1 spark plug and insert a screwdriver to feel the top of the piston. Continue turning the crank until the screwdriver stops rising. That will be No1 tdc. If you inadvertently go past tdc, continue cranking slowly for two more revolutions until you reach No1 firing tdc again.

[pendragon374]

Thanks to you all for responding. I have had another attempt this evening with the new information. I set everything to just before TDC and inserted the dist to just about to open on number 1 lead and nothing. So I lifted up the dist and moved it one tooth at a time before eventually the car started but was back firing and very revved up. I continued to move teeth before it would not start and I moved the dist one tooth at a time again before it started but same as before. At one point when it was at high revs I turned the ignition off to stop the car and it carried on running causing me to pull the coil plug lead to stop the car. At a bit of a loss now.

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May I ask. Are any of the forum members who are in the know near to Lytham , Lancashire who might be able to call around and give me some assistance/advice ? John

[John Mason]

In your first post you mentioned that you had installed a new wiring loom. I would check that you have all the connections correct particular the ones to the ignition circuit. You say you switched off the ignition but the engine still continued to run. There must have been a circuit of some sort to continue making a spark at the plugs to keep the engine running. The only other way I know of an engine running after the engine has been switched off is when a build up of carbon in the head has got so hot it acts like a plug and ignites the fuel mixture. I don’t think your engine had run long enough to get that to happen.
You could try laying a plug on the head so that the body earths and with a plug lead attached turn the engine over WITH IGNITION OFF and see if the plug sparks. This would prove if the ignition switch is breaking the circuit. This is best done in the dark as it is easier to see any spark created.

John Mason.

[Dave Mann]

I had a car where somebody had replaced the SA1 ignition/light switch with a modern one not having winter/summer charge, once started the only way to stop the engine was to disconnect the feed to the coil as the the dynamo was feeding the ignition. It took an age to sort out as all the wires were black and nicely harnessed.

[Reckless Rat]

There is no need to remove the distributor completely and then "move it round a tooth". The base plate should be left in position (that fixes the distibutor to the dynamo end casting. All you need to do is to loosen the horizontal clamping bolt, which then allows you to rotate the distributor in order to advance or retard the timing. If you have already succeeded in finding a point where the engine will start, all you then have to do is rotate the distributor body in order to find the sweet spot.

With the engine at TDC, and n°1 piston at compression, the end of the rotor arm should be pointing at the n°1 plug lead terminal inside the dizzy cap, and the points just about to open. It should start. If it doesn't then there's something else wrong. I would replace the electronic ignition unit for a set of points as a first test. You can't tell whether an electronic one is any good - they either work or they don't.