924Board.org

Gus · Joined: 21 Sep 2010 Posts: 25 Location: Seixal, Portugal

Some weeks ago, my car developed a subtle problem, which I hope someone can help me track down.

Sometimes, when I started it, there was a hesitation between turning the key to start and the starter actually starting. The first few times it was a second or so, which gradually grew to a few seconds until one day it didn't start at all.

I though it was the solenoid on the starter, and proceded to remove it. Well... it seems it isn't the solenoid. The starter seems ok, and when I tested it outside the car, everything works fine.

While I was under the car, I tested the all the cables with a voltmeter and they all seem to be ok. I didn't test them for resistance, but after I refitted the starter on a let's-try-this-again whim, it worked perfectly.

So, my question: what is going on? What could cause this hesitation and eventual total stoppage, and what did I do to fix it. I actually don't think I fixed it and it will stop again, which is why I would love to hear an opinion on this...

Gus · Joined: 21 Sep 2010 Posts: 25 Location: Seixal, Portugal

Btw, I also tested the ignition switch, it came out fine...

Paul · Posted: Mon Nov 08, 2010 11:01 am Post subject:

Check the battery to body ground and the body to motor ground.
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

Smoothie · Posted: Mon Nov 08, 2010 11:45 pm Post subject:

If that doesn't fix it (and I'd add: clean both battery post connections), then dirty solenoid could be part of the problem (if you didn't happen to disassemble and clean it while the starter was removed).
_________________
"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

rkn · Joined: 01 Apr 2007 Posts: 176 Location: Copenhagen

I just replaced my starter, which also drove me crazy. It would work nicely out of the car but when installed it would sometimes work fine, sometimes be slow, sometimes fail competely. The solenoid was fine but it turned out the motor brushes were worn. If you have your starter out of the car, open it up and have a quick look.
_________________
1980 924NA ROW

Gus · Joined: 21 Sep 2010 Posts: 25 Location: Seixal, Portugal

Hi, thanks for the responses.

I haven't had time yet to check on things, but the ground straps seem like a good ideia.
About the solenoid and brushes: I removed the old starter precisely to do this, but the three screws attaching the solenoid to the starter's frame are corroded and fused. Someone has obviously tried to remove them and ripped the slot in the head of the screws, so I have no traction. Penetrating oil has done nothing for it, either, so... I kinda gave up. Any tips on removing corroded in screws are welcome.

Scorpio · Posted: Tue Nov 09, 2010 10:39 pm Post subject:

New starter motor will save you alot of time and hassle
_________________
1979 NA
MS1..EFI..
GARRETT T25 TURBO
BILSTEIN SHOCKS
GT BASED CUSTOM BODYKIT

Brisbane , Australia
Think mean think fast
all youll see is
my Porsches Arse!!!

rkn · Joined: 01 Apr 2007 Posts: 176 Location: Copenhagen

+1 to scorpio.

Meanwhile just drill the heads off the three screws and get some new ones.

The brushes are inside the motor itself so they can be checked without removing the solenoid: remove the two long screws on the back of the starter and loosen the back end by tapping it gently with a hammer.
Carefully pull the back section from the body and you will find the brushes down there.

Then go buy a new starter
_________________
1980 924NA ROW

Gus · Joined: 21 Sep 2010 Posts: 25 Location: Seixal, Portugal

Ok, this is the embarassing bit: I did get a new starter.

I found one on ebay from what seemed a reputable seller in germany (I live in Portugal) and it arrived on friday. It's slightly different, smaller though the frame is obviously identical to my original one. The wire contacts are not marked but by the location they seem kinda obvious, yet I can't get it to work.

I'm not sure if it's due to me being a noob and doing some really basic mistake or ... I got shafted

.

When I get home I'll try again...

BTW, confirm my method please, to test one of these outside of the car, with a battery: Positive to big 12V connector on starter, negative to frame and... how much to the start connector? can I connect another wire straight from the positive? Can I test it without anything connected to the second small connector?

MikeJinCO · Posted: Wed Nov 10, 2010 1:16 am Post subject:

Yes, positive on battery to the solenoid, battery negative to the starter frame and then just use a large screwdriver to jump from the positive to the other large lead on the solenoid(that goes into the starter). It should spin. Hold the starter down with something so it doesn't jump around.
_________________
Mike

'67 MG Midget Dp
'71 Ocelot Dsr Kawasaki 1000(under rebuild)

MikeJinCO · Posted: Wed Nov 10, 2010 1:54 am Post subject:

I should add, that will only check the starter, not the solenoid. I don't have a starter around now, but there should be two small leads on the solenoid. One should be hot, jump to the other and that would check the solenoid and start spinning the starter.
_________________
Mike

'67 MG Midget Dp
'71 Ocelot Dsr Kawasaki 1000(under rebuild)

Gus · Joined: 21 Sep 2010 Posts: 25 Location: Seixal, Portugal

That's precisely my doubt:

1- The haynes manual only mentions 2 electrical leads, though the circuit diagrams show 3 connections.

2- The original starter has 4 wires connected:
2.1 - one from the ignition switch to a small connector on the side of the solenoid
2.2 - one big gauge wire straight from the battery to the big connection on top of the solenoid
2.3 - a thinner wire also connected to the big connector, together with the big battery wire, which I haven't tracked down were it goes yet
2.4 - a thinner wire connected to another small connector on the side of the solenoid, which seems (not 100% sure) to got to the ignition coil. Weird thing about this is: the connector on the solenoid seems to be a dummy, not connected to anything. Next to it there seems to be an input into the solenoid, without a connector, but which has a plate connecting it to the 12 volt input on the starter.

So that's 3 connectors on the solenoid, one of wich seems to be a dummy.
On the new starter I have 3 connectors, all valid and unlabeled, though the big battery conenctor is obvious.

Re-reading this post it occurs to me I'm missing pictures, this description is a mess. If I get a chance tonight I'll take some and post them.

!tom · Posted: Wed Nov 10, 2010 11:24 am Post subject:

2.3 should go to the alternator.

You're right about 2.4; it provides 12 volts to the coil when cranking. Otherwise, the coil is powered through a ballast resistor so that it doesn't burn out.

Often times people here refer to the connections as they are referred to in the Hayne's wiring diagrams.
_________________
78 924 NA
5-lug

Gus · Joined: 21 Sep 2010 Posts: 25 Location: Seixal, Portugal

Ok, got the new starter working, by simply leaving one of the connectors without any wire. I would love to know what that connector is for (none of the connectors are labeled) , but the damn thing starts now. Hope I don't find out it was necessary *after* I reassemble the multiple protection plates and exhaust

Anyway, thanks to all for the help, you got me to do what I should done in the first place: think carefully and observe. The 2.4 wire, on the dummy connection, just goes back to the positive end on the battery, it's one of those extra wires one finds attached to the clamp. I just ignored it and attached it somewhere where it wouldn't do any harm, I guess it's there more due to legacy than any real use...