Strange starter failure?

[2tmike]

Came to start the S4 yesterday after a couple of months in the garage and got a clicking starter and nothing more, no cranking. The engine is free and can be turned over by pushing the car in gear.
The car has a pre engaged starter fitted which, from the receipts with the car, came from SJS a few years ago and has been working fine until now, probable for a thousand miles or more. The battery has been on maintenance charge and has never given any problems and nothing visually is amiss. After checking and trying a few things without success I took the battery from my GT4 and connected it in parallel with the elan battery. With this the starter just turned the engine over but very slowly, not enough to fire it up. Bypassing the starter solenoid gave exactly the same result, so I'm fairly sure that the problem lies in or around the starter itself. After a few moments cranking both batteries gave up and I checked cables, starter etc for heat but strangely the only areas that were even warm were the jump lead clamps. I put the battery back on the GT4 and it started easily with a stone cold engine.
Does anyone have an idea what could be going on ? All was absolutely fine when I last used the elan 8 nor 10 weeks ago.
Thanks
Mike

[69S4]

Those symptoms make me suspect an earthing issue.

[seriouslylotus]

Old battery died?
Try disconnecting old battery and use a know good one

[nmauduit]

you may want to check actual voltage while cranking, as near as possible to the starter (say out from the solenoid if starter not reachable underneath) and see from there. Also the size (resistance) of the jumper cables is to consider for the not starting while jumping (it heats where there is a resistance point, could be inline resistance or contact resistance).

[lotusfan]

+1 the earthing issue as suspected by Stuart.

Instead of connecting the other battery across the existing battery in the boot, to prove the earthing issue you would do well to use the jump leads to connect the other battery to the battery side of the starter solenoid and a point on the engine block.

If it then starts like a good 'un the problem is probably the main earth point to the chassis under the boot floor.

[2tmike]

Thanks guys for the quick responses.
I didn't explain too well perhaps, but I did connect a good battery directly from the starter solenoid output terminal to starter and earthed to the block as suggested and the result was exactly the same, very very sluggish engine turn over. In this situation the existing battery, solenoid etc are out of the circuit.

[lotusfan]

Thanks guys for the quick responses.
I didn't explain too well perhaps, but I did connect a good battery directly from the starter solenoid output terminal to starter and earthed to the block as suggested and the result was exactly the same, very very sluggish engine turn over. In this situation the existing battery, solenoid etc are out of the circuit.

In that case, assuming that 12 volts is at the starter terminals, it sounds like a sick starter.

[2tmike]

12.2V at the solenoid.
If it is a dead starter what puzzles me is how it could fail just sitting i the garage!!!!

[seriouslylotus]

12.2V at the solenoid.
If it is a dead starter what puzzles me is how it could fail just sitting i the garage!!!!

12.2V is quite low
Try with old battery disconnected as it will draw some of the new batteries power away from the place its needed.
Cheap and easy to check

[2tmike]

Did that as well, no noticable difference sadly.....

[nmauduit]

12.2V at the solenoid.
If it is a dead starter what puzzles me is how it could fail just sitting i the garage!!!!

12.2V is not enough imho, esp. in winter when the oil is cold hence of higher viscosity.

huhmidity can create oxidation over time, at wire junctions (or worse within) but also inside components like the solenoid, then the contact resistance increases and not enough current goes through to do the job. Also a dead battery with good harness (low resistance) can sink some of the current of the fresh battery trying to jump the system...

[collins_dan]

I had a similar problem. Did you check voltage at the starter? 12.2 is low for a pre-engaged starter without running through a solenoid or relay. Remember the pre-engaged starter has to first push in the pinion, then once in, it turns it over. Your pinion is likely not going all the way in due to low voltage, or something obstructing. It is sat for awhile, it is likely grounding related. I could never find exactly where the grounding problem was on mine, so added a relay (a solenoid would work as well, just something to make sure full battery charge reaching the starter) and a good battery and has been fine ever since. Good luck. Dan

[2tmike]

Thanks everyone for the ideas and suggestions. My measurement was at the solenoid with the elan battery in circuit and I agree 12.2V might be a little low. However, disconnecting the elan battery and connecting a fresh one with +ve straight onto the starter cable and -ve onto the block made virtually no difference . The engine cranked very very slowly for a few revolutions and then stopped as if the battery was dead. So, the elan wiring, solenoid, earth straps etc were not involved in the process. Just the battery, jump leads, cable to the starter and the starter itself. That battery then was put back into the GT4 and started it easily, and just for fun I connected the same battery up to the GT4 via the jump leads, still no problem turning the engine over on that car.
I'll put a couple of batteries on charge tonight and give it one last go tomorrow and will remeasure voltage both sides of the solenoid just to see what it looks like. Any other ideas very welcolme !!!!

[prezoom]

If your pre engaged starter is like mine, the solenoid has a rubber vent tube coming out the side. My vent tube fit loosely in the hole, which allowed it to slip between two discs that transfer the electrical current from the solenoid to the starter motor when the solenoid is engaged. When this happened, the discs could not make contact and no current was delivered to the starter motor. It took several installations and removal of the starter to finally determine what was going on. Wound up removing the vent tube and replacing it with a rubber plug. No problems since.

[2tmike]

Thats an interesting one !!! As far as I can tell looking at pics , the starter on mine is a Wosp LMS113-9. I think that these are also sold as Powerlite but I think Wosp is the manufacturer although I could be wrong. Can you see the vent tube with the starter installed on the car and would you be able to tell if its in the correct position?