Starter woes

[1BHP]

I've had a couple of starter issues over the wkend - I drove 130 miles Thursday night, come Friday morning I went to start and nothing, voltage read 12+v lights etc working, but starter not turning at all. Jump start from another car started almost immediately, assumed I'd left something on over night which had drained the battery just enough. No issues for the rest of the wkend, passed MOT, multiple short trips stops and starts. Drove back into London yesterday morning, all good until I pulled up at the garage, switched off engine for 2 mins and when I returned exactly the same - voltage but nothing from the starter. Called RAC, checked battery, seemed fine, earth ok, alternator ok, current at starter motor and started when starter motor hot wired - then started several times immediately after unaided...

Not really sure what to do next to find the root of the problem, could it still be a duff battery? bad connection from battery to starter motor? Kev had mentioned adding a relay for when starter gets hot...

Would love to get an answer oneway or another as I'd hoped to take in on holiday this wkend...

any thoughts or experience of similar?
thanks. Ben

[abm914]

I had a similar experience ages and ages ago. I never actually found the root cause but I did check, clean and reseat all the electrical connections on the starter and the relay (that had been fitted by the previous owner). I did this twice, after the first time I was still having the issue but when I did it again, never had a repeat since. Not sure if this was the actual issue or not but worth checking.
Else, check the gearbox to body earth lead, or it could be a sticking solenoid (and when you have the extra juice from jump starting, this frees it off).

Ad.

[middlefour1]

Hi Ben,

Kev's right, fit one of these, had one on my car for years.

http://www.autoatlanta.com/Porsche-hot- ... -RWR1.html

You can make one up yourself but this is a complete kit and works a treat!!

[914 KEV]

The problem is with the starter solenoid, not the battery, common problem with the 914.

When the solenoid gets hot from heat transfer from the engine and exhaust system, the electric winding resistance increases, which cause more of a voltage drop.

The normal 914 wiring to the solenoid takes the long route, from the battery to the ignition switch then back to the engine bay relay board then to the solenoid.

There are many causes for a voltage drop on the way: ignition switch: wiring length: wiring connections: relay board and then the extra voltage drop at the solenoid.

I suggest removing the starter motor; lubricate the pinion shaft bearing with a few drops of oil and operate the starter motor using jump leads.
This may help.

Fitting a relay to switch the power to the solenoid improves the amount of voltage getting to the solenoid as it will only have to travel a short distance with the minimal of connections.
The relay also saves the ignition switch, as every time it operates the starter it is switching around 14 Amps and this switch fail due to the heavy switching.

Even the Porsche factory workshop manual mentioned adding a relay and even shows a wiring diagram and how to add it to help cure the problem of operating the solenoid when it is hot.

[1BHP]

thanks Kev,
Are there any fitting instructions online anywhere I can have a look through? Does anyone know of any UK suppliers that might carry the Hot Start Relay Kit or similar from the autoatlanta link above?
B

The problem is with the starter solenoid, not the battery, common problem with the 914.

When the solenoid gets hot from heat transfer from the engine and exhaust system, the electric winding resistance increases, which cause more of a voltage drop.

The normal 914 wiring to the solenoid takes the long route, from the battery to the ignition switch then back to the engine bay relay board then to the solenoid.

There are many causes for a voltage drop on the way: ignition switch: wiring length: wiring connections: relay board and then the extra voltage drop at the solenoid.

I suggest removing the starter motor; lubricate the pinion shaft bearing with a few drops of oil and operate the starter motor using jump leads.
This may help.

Fitting a relay to switch the power to the solenoid improves the amount of voltage getting to the solenoid as it will only have to travel a short distance with the minimal of connections.
The relay also saves the ignition switch, as every time it operates the starter it is switching around 14 Amps and this switch fail due to the heavy switching.

Even the Porsche factory workshop manual mentioned adding a relay and even shows a wiring diagram and how to add it to help cure the problem of operating the solenoid when it is hot.

[914 KEV]

Are there any fitting instructions online anywhere I can have a look through? Does anyone know of any UK suppliers that might carry the Hot Start Relay Kit or similar from the autoatlanta link above?

I can make you a similiar one and even fit it.

[rusty914]

Are there any fitting instructions online anywhere I can have a look through? Does anyone know of any UK suppliers that might carry the Hot Start Relay Kit or similar from the autoatlanta link above?

I can make you a similiar one and even fit it.

Are you taking orders/bookings Kev ?

[jonat127]

Yea, I did the Kev relay and also fitted one of these http://www.autoelectricsupplies.co.uk/p ... tegory/139 has been brilliant since.

[914 KEV]

Are you taking orders/bookings Kev ?

Now that is an idea.

Can fit one of my disigned Hot Start Relay conversions to your six on Sunday Morning.