Clicky noises when turning the key

[1540phil]

Right.
Had some starting problems with the old 944, and we decided to let it rest over winter with a nice sorn notice.

Brought her out to give it a go and noticed a series of mysterious clicks coming from the fuse box when trying to start her. So I thought I would describe the event to get some clarification on what should be happening.

When I put the key in the ignition I hear a click from the relay area when the key is fully inserted.
However this sometimes makes a number of clicks as though the key is not completing the connection properly.
When I turn the key there is then a series of multiple clicks that come from the relay area when the key reaches the extent of the turn.
I don't think this should be happening but I don't know what series of events should happen when putting the key in and turning.
I.e. should the relay click when the key is out in? Should it click when turned? Should the clicks happen as though the key is not in fully?

I have read some comments that the DME relay is a common cause of starting faults and the is mention of making a 3 way bypass.
Is this just simply a bypass that joins all 3 terminals of the relay at once? Will this cause any damage if left connected for any length of time? Does it start the fuel pump circuitry etc? Which terminals can be left connected so I can leave the third as a switch?

Oh and lastly, where is a good place to get a new DME relay and which one is the best. I have heard talk of getting a newer version?

For info this is happening on a 1983 944 square dash.

Many thanks.............

 

[pauljmcnulty]

If the battery is nearly flat then you will get a series of clicks from all the various relays rather than the car turning over. I know, with my battery drain problems I had this every time I got in the car!

 

[simdel1]

My first thought was battery too. Try charging the battery or jump starting the car with a healthy battery.

 

[bmnelsc]

Sounds like low (not totally dead yet) battery. If it has been low and then sitting over winter, recharging needs to done in a particular way to avoid sulphating the plates in the battery (if its not too late).

You can get battery maintainers that are used to provide a very low "maintenance" charge to full batteries and also provide a decent charge rate for low batteries. Many have a "de-sulphate" capability where it will provide a pretty high voltage over a specified period in an attempt to remove the sulphates from the plates by chemical reaction.

These are not terribly expensive (in Canada I got one for about C$45) so you might want to look around. Even if you have to replace your current battery - having a maintainer will keep your new battery in good shape. When your car is not used frequently, the cycle of drain when it not in use and then rapid recharge from driving shortens the life of your battery by quite a lot.

 

[jonnyporsche]

I agree look at the battery first. Mine was showing full charge on my charger but would not hold charge during its MOT needed a boost charge at the garage. Just bought a sparkling new battery. Bingo.

 

[1540phil]

We have killed the battery tryin to start it.
It was fine and fully charged before we started. Now being intelligently charged.

We have had this problem before, intermitently, but thought we had solved it with a new speed sensor.
Obviously not!

 

[VanhireBoys]

Hi Phil... I am with the lads on this .... Try another battery as I have seen before where a battery fully charged will not deliver the current ... It takes quite a bit of current to spin over a 2.5 ltr engine !

If another known good battery does the same its a case of looking at the diagram and working it out from that... Dont keep the DME relay bridged as the fuel pump will be running all the time and this is not good..

Best place to get a spare DME relay is a Porsche dealer - At least you know what you are getting.. []

Is there an aftermarket immobiliser fitted ...? These are notorious trouble spots...

Let us know how it all goes !

 

[1540phil]

With the previous starting problems we were seeing no movement of the rev counter.

Could a problem with the dme relay cause this?

I.e. does the dme relay control the spark output, and other electrical circuitry as well as the fuel pump?

Battery is still charging so I'll have a play when it's finished.

 

[POR1983]

Yup, it's not all about volts it's about amps too, my battery was showing 13.8volts but was way down on amps, all I got was a clicking sound from the relay, new battery sorted it.

 

[Mike_Pollock]

If the tacho isn't bouncing the speed sensors isn't working, or the connectors/cables.

 

[Hilux]

If a cell has gone in the battery it wont have the oomph to start it

 

[1540phil]

Thanks A9XXC

I am sure there is a problem other than the battery.
We replaced a speed sensor and it started first time.

But back with starting problems again.
I just wondered where along the electrical circuitry the ignition and dme relay featured.
Meaning could it be an ignition barrel failure? Dme failure? Or any other electrical components than the speed sensors?

Does the system start with a connection in the barrel? Does the dme relay activate the ignition process? If this has failed would the rev counter still bounce when cranking over?
Just trying to understand the ignition series.

 

[Mike_Pollock]

As I understand it - and I'm not the expert - the ignition switch energises the DME relay, which in turn energises the fuel pump, for a brief period and the coil etc. the ignition unit then looks for a 200rpm signal from the crank sensors, before sending the signal to fire the coil and hence light the plugs and also turn the fuel pump properly and the engine runs.
There are 2 crank sensors and I don't know if they are connected, or exactly where the feed for the tacho comes from, but if they don't bounce the tacho needle, the car won't start, however fast the starter spins it.
What year is the car and I'll see if I can find a suitable diagram.

 

[1540phil]

It's a 1982 944 lux.

 

[Mike_Pollock]

I have a .pdf for '84, which I think will be the same. So email me at A9XXC@aol.com and I'll send it on.

 

[Paul 290T]

I had the same symptoms on my 86 turbo.

In response to the problem the Indie (having cleaned up all earth cable connections without success) decided to do a starter motor refurb, but he also opted to change the battery as it had a bad cell. The problem has not re-occurred. So whilst I would recommend the battery first, if that's not the answer a starter refurb, after cleaning up all earth connections would be the next thing to try.

The starter incidentally was the original. It was found to be full of dirt.

I seem to remember that the DME does not stop the engine turning over, but since no fuel pump operation occurs with a bad DME it'll not start.

 

[1540phil]

Thanks Paul.

I think I have entitled the thread badly.

The ignition clicks were noticed when the battery was flat, but I was trying to identify any bad circuitry.

It's whether the ignition/relay/sensor/spark problem could be anything simple.
Don't really want to spend £240 on 2 sensors to find out its a relay issue!