A 1964 OTS that belongs to a friend of mine has a very mysterious, to us, starting, or lack of starting, problem.

This is a 3.8 car, very original, which he has owned and driven for about three years, and has undertaken some upgrades. Among other things, he installed a new 5-speed gearbox, Petronics ignition and new battery. The car is positive ground. It was a sweet running car, I drove it, and no starting problems until the above work was done. Now, when trying to start it, the engine barely turns over and there is what sounds like a backfire and vapor sort of billows out of the rear carb, but still no start. We jumped it to his truck, from truck battery to car battery, with the truck running, and just barely got it going. It sounds fine when it's running. Battery is charging.

The new battery has 750CCA and reads 12.6 +- with a volt meter. He cleaned paint from the ground connection to the chassis, with a little better result but still no start with just the car battery.

Same results with clutch in or out, gearbox in neutral.

Timing? Starter? Battery? God forbid, the gearbox.

We have run out of ideas.

 

I would think the first place to look is the starter motor and it's connections to the battery. If the starter motor only turns over very slowly, it could be a high resistance in the supply line, OR the earth return. As these are pretty simple cars electrics-wise, you could go round with an AVO meter and check the lines to see if there is any resistance.

I once had an XJ6 with a very bad connection on the battery earth. It was where the line clamped to the body shell. Other place to look is the engine-body earthing cable. As it runs fine when finally started, I would not think the new ignition system is to blame. I would not think the oil drag in the gearbox on engine-start is anywhere near sufficient to slow down the starter motor.

It might be worth checking the starter motor out too. I had one failing and eventually another one was fitted and cured the problem.

PS: a bit more detail on what work has been carried out might help too.

 

First , the battery should be at about 13.5 volts, so it may have a bad cell...12.6V fully charged is too low.
Timeing is the other thing...If you can get it started and warmed up, your timeing should be about 10 degrees at idle....One or two degrees less won't hurt, but 12-14 degrees will give you problems....
If you rev the motor, does it smooth out? If so, you may have a vacuum leak....
Check that all the carb nuts to the manifold are equally tightened.
Also, check that all the intake manifold nuts ...Make sure you don't overtighten, but good and snug does it.
Check your dashpots, and make sure there's oil in them...Check to see the carb pistons are falling freely.
They say that 99% of so-called carb/fuel problems are really ignition problems, so consider using a different coil...I would go ahead an purchase one, and put the other away for a spare....
Let us know what cured it.

 

Thanks for the informative replies. I have passed them along to my friend who is entertaining visiting relatives this week, so the E type is getting no attention. Next week we'll be back on the problem and I'll let you know what we find out.

 

The first thing I would do is make sure the tranny swap isn't putting anything in a bind. Can you easily roll the engine by hand slowly?
After that, starter motors in general are bulletproof devices if not over cranked, but there is an Achilles heel. It's the brushes, most starters have 2 sets of brushes, and 4 magnets(in the form of field coils, or permanent magnets). When the brushes wear to their service limit they begin to lose contact with the commutator. When the first brush loses contact the starter loses 1/2 of its power since each pair of brushes represents a complete starting assembly, albeit both housed in a single starter frame.
Often the end cap that houses the brushes can be removed without pulling the starter, for inspection. If the motor has permanent magnets the only internal wiring will be to the starter wire post, if however it is a field coil type motor you will have to disconnect the field wires from the brushes as these will be wired in series, in from the post to one side of the brushes, out the other side of the brushes, to the fields, through the fields, then to earth(usually in the form of a set of wires bolted to the brush frame).
Reassembly poses some quality issues it pays to be aware of. In the first place there will be washer/s on the starter shaft, retain these making note of the order and orientation they were originally facing. Oh and there will be copious amounts of black, nasty, brush dust when the cap comes off.
Finding replacement brushes should be easy even if you have to make them yourself from a close facsimile.

 

My 2 cents - The battery & connections are the obvious ones. If the starter motor wasnt touched during the upgrade there is little reason to believe it has suddenly gone bad.

Check that ignition timing. Lots of people put the pertronix in incorrectly, so it's trying to start 10deg from where it should be. An easy check is to loosen the clamp on the distributor and turn it by hand. Start with a tad clockwise and see if that works better for you. Tad = 5-15 deg.

Let us know how you get on !