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TR2/3/3A 56 TR3 Starting Issue

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mgedit

mgedit

Jedi Knight
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Until a couple of days ago, car has been turning over quickly and starting right away. Now it still starts, but very slow to turn over. Went from working great to causing grief with no warning and no slow degradation of performance. Getting drop in voltage at battery to about 10.5 V or so when cranking. Regular battery voltage is 12.9 V. Have checked all connections and all seem tight and clean. Will take all apart and clean to be certain, but that does not seem to be the problem (all connections are essentially new as I've only got about 2000 miles on car since restoration). Think either the solenoid or starter (old bomb style, which was rebuilt) has failed or needs attention. My question is: How do I determine whether it is the solenoid or the starter that is the issue?

Cheers, Mike
 
If you have the original style solenoid with the rubber button on the back you can manually work the solenoid. Alternately you can 'jump' the solenoid by resting a big screwdriver against the lower post then bringing it into brief contact with the upper post. This will create sparks and possibly damage the screwdriver so use caution and an old tool. That latter method takes the solenoid completely out of the equation.

Obviously, all of the the above is done with the gearbox in neutral.

But from your description the starter may be the more likely culprit. Pretty easy to open these up and have a look at the parts (though you say it was rebuilt). Worn rear bearing, failed rubber thingy on the pinion end, worn insulation on the field windings and worn commutator are common faults I have seen.
 
Probably not the culprit, but did you check the ground strap from the engine to the chassis, down by the left front motor mount?

I had one come apart once and the car didn't turn over well until I put in a temporary wire from the ground post of the battery to one of the nuts on the valve cover. That restored function of the starter well enough that I left it there for 21 years, until I got around to installing a new braided engine ground cable.
 
Thanks for the input. Will continue to investigate and report back. Cheers, Mike
 
With a bad connection you will still able to see 12v everywhere but the starter use a surge of 400 Amps and this courant are maybe not able to pass from the battery to the starter, as mentioned with a bad connection of the ground strap the starter don't have a good mass. Easy to shunt the solenoid with a cable as test. One possibility too is a dead battery, deliver enough current for a radio but not for a starter, ( bad connection on the battery is also a classic ).
 
Any time a battery is over 3 years I suspect it. Over 5 years I just replace it first thing when I have starting issues. Anything I get past 5 years I consider borrowed time.
 
Agree totally about Johns battery life comments- especially in warmer climates
 
CJD said:
Any time a battery is over 3 years I suspect it. Over 5 years I just replace it first thing when I have starting issues. Anything I get past 5 years I consider borrowed time.
Click to expand...

That's because it's too darn hot down there. It's not unusual to get 7 or 8 years out of a battery here in the deep freeze.
 
Just a quick follow up. Rather than just making sure the grounds were tight, i took all apart and made sure they were contacting clean bare metal. Seems to have cured starting issue ... at least for now. Thanks for the suggestions. Cheers, Mike
 
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