Help , I have just bought a Ruby , my first A7 . The previous owner has had the engine rebuilt , by a well known A7 man , and fitted the ancilleries back on . I bought it minus the spark plugs - see previous message . I bought some plugs , drained the old petrol and put new in the tank and float chamber . I have timed it up as per book ( twice ! ). It will pop and bang , and occasionally give a big backfire , but will not go - what have I done wrong ?? Thanks in advance , Joe

Think not "what have I done wrong", but "what did they do wrong", don't be fooled into thinking because a well known person (to whom?) has done the work it is always correct. (Duck now as I find out it's one on my best friends....).

Sounds like either the timing is out (180 deg.) or the cam gears are incorrectly set up, this is assuming all the valves are going up and down (not stuck) and the valve clearances are correct at about 6 - 7 thou., and that the firing order is correct.

Just to start with.......

Naomi .......

Thanks Naomi , I think I have been a silly boy in my haste to get it going !! I'm 99% sure I've timed it 180 ' out , I have set it on the induction stroke and not the power ! Still , people who don't do anything will never make mistakes !!! Thanks again , Joe

Hello Joe,
Just to follow up Naomi's comments, and with a fair amount of use of the crystal ball and other like appurtinances to enable a diagnosis to be made from "across the seven (A7?) seas," I think I would firstly recheck the ignition timing. As Naomi indicates, a 180 degree error is very easy to arrange.

You need to be sure that you have timed the engine at around the TDC point, in accordance with the "writ" on these matters. But as you probably already know, the TDC mark on the flywheel indicates TDC, alternately, on both the compression stroke and the exhaust stroke. Naturally for timing purposes, you need to ensure that you are on the compression stroke, conventionally on No.1 Cylinder.(which I will use in the rest of this diatribe).

The simple facts are that when the flywheel mark 1/4 is artfully arranged to be in the "timing" position, the engine may be at TDC Compression Stroke on No.1 Cylinder and TDC Exhaust Stroke on No.4 Cylinder or vice versa, and you need to know which, otherwise your timing could be 180 degrees out. Given the certainties of Sod's Law as applied to A 7 maintenance, a 180 error is quite likely.

The compression stroke is able to be "sussed out" as the stroke on which both valves for the particular cylinder are "closed" which admittedly may be a little inconvenient to view.

You can also find the compression stroke by removing the spark plug from No. 1 cylinder, and using your thumb placed over the plug hole while turning the engine over with the starter handle slowly, you will feel the compression pressure build up on the compression stroke.All the above will be made easier with an extra pair of hands (or more)and the presence of other people is convenient in other ways. You will have someone available to blame and abuse if things go wrong, and, if things go right you will have a layed on,impressed audience to wonder at your arcane talents, wisdom, knowledge and abilities, which you should do nothing to dispel.

Once you have found the right stroke, and arranged the right opening point for the distributor contacts, it would be well to ensure that the rotor button in the distributor is aligned in the direction of the segment in the cap which has the lead connected for No.1 cylinder spark plug. It would also be a good time, once the lead going to No. 1 is checked out OK, and it is a simple matter, to ensure that the other cylinders have their spark plug leads connected in the order 1, 3, 4, 2 clockwise, looking from the top, around the distributor cap.

Given all the above is OK, hopefully, the engine may fire.

If not, a more extensive check of the valve timing might be required, but here's hoping we don't need a further chapter.

Good luck,

Barry R

Hello Joe,

I wish I had waited a few more minutes before
replying.

Hope it all works out OK for you.

Regards,

Barry R.

Joe, are you a member of a Club and if so, are there no members local to you who may be able to help?

You don't have to answer, but which County are you in - if in UK even - this is an international Forum for an International car, so you could be anywhere, I mean look where Barry is, presumably he thinks we (in the UK) are out on a limb.

Phil.

Steady on Phil. Legless, maybe. Out on a limb, never! Regards,
Barry R.

It goes , and runs beautifully !! I was 180 degrees out , it all seems worth the blisters now though !! I just need to get the starter to turn it over and I'll be laughing !!! Thanks again for your help , Joe

Joe,

A common cause of difficulty in starting is a poor earth. Make sure that the earth strap from the battery is connected to the engine by heavy (starter-type) cable or copper braid. Don't just rely on the strap being attached to the battery box, because the return current from the starter motor will have to struggle back through layers of paint/rust/rubber/felt etc. Also make sure that the contacts in the starter switch are clean.

David