Intermittent starter motor

[Captain flint]

Hi all,
Having previously posted a topic on my stater motor problems I took
all the helpfull advice kindly offered.But problem is still present.
I have fitted a new Lucas starter motor.
I have fitted a new Lucas battery,53 cranking amps.
I have fitted new earth lead from starter motor to chassis.
I have checked the timing.
I have checked all leads.
The problem is,sometimes the motor spins the engine over fast,other times it barely turns it over at all!No matter hot or cold.
Before I changed the engine from 1098 to 1275 I never had this problem!
Help!
Regards,
Martin.

[Big Jim]

Do you always start it with your foot off the clutch ?

[don58van]

This sounds like a faulty solenoid.
Don

[oliver90owner]

Has nobody advised that a voltmeter is far, far cheaper than all those advised 'fixes'?

I do hope your new battery has more cranking amps than 53!

I would have advised you to use a simple voltmeter to isolate your problem, before spending any money on expensive parts.

You do not mention earth lead connection from the battery to chassis. That is yet another simple fix, were it found c to be the problem.

If your starter motor was operating too slowly, and was faulty, the current draw would either be excessive , due to the starter, or there would be a high resistance within the starter. So the first check is to measure the battery voltage when operating the starter motor - as the battery voltage drop is indicative of current load. The state of the battery can be checked (if the voltage drop is excessive) by applying a heavy external current load and measuring the voltage (any good service outlet can test a battery in minutes - the actual test takes about 20 seconds).

If the battery voltage drop indicated a low current draw, then the starter could be checked with careful use of jump leads (ideally with a separate solenoid switch of known 'good operation'). If the fault is isolated by this, one jump lead from battery live to starter motor checks the feed side and the jumper from battery to earth checks the earth return part of the circuit.

Fix as appropriate. Usually a high resistance in the feed/return from/to the battery will be found either by use of the voltmeter or by the offending joint/connection becoming warm or hot (battery terminals can be melted in serious cases).

By this time you should, by now, have isolated and fixed the problem or know what part you would now need to purchase. Far better than taking 'helpful' advice and buying all those unneessary parts you have paid for. Yes, diagnosis is the cheap part of any repair on these simple circuits.

Even the vain suggestion of incorrect timing is easily discarded by simply disconnecting the coil feed wire and testing the starter withono possible ignition spark. Simples, really.

RAB

[IslipMinor]

Martin,

Where are you based? Someone might be able to help locally.

[Captain flint]

Once again great response,thank you all.
I will get cracking on latest comprehensive tips,lot to get through!
I am based in Fetcham Surrey, KT229RL
01372379292 if anyone can drink endless cups of tea,or something stronger if not driving!
Best regards,
Martin
Yes I had a senior moment,I meant 530 cranking amps!.

[smithskids]

Check the amount the starter bendix goes in when it is turning. If it is going in too much it tends to jam against the flywheel teeth.