ninefiveone

I need ideas here.

Since my clutch job last october, I've been through 4 starters.

Starter #1: The oem starter had reasons to die: lots of cranking trying to diagnose bad ref sensors and lots of heat from a new exhaust and hard track usage.

Starter #2: Might have a reason to die, we figured this confirmed the heat theory. This lead to a replacement with lots of heat shielding.

Starter #3: No clear reason to die but I was willing to pretend it wasn't indicative of a problem and just replace it.

Starter #4: Started the car right after I installed it, and then again when I went for a celebratory 45 min drive. Won't start the car anymore.

Symptoms: No solenoid click, nothing. Just the sound of the fuel pump when I try to start it. It'll push start fine. The second starter we put on a bench and it would spin when power was applied. I don't have the ability to do that anytime soone with starter #3 or #4. I do have a running problem where every 10th start or so the motor bogs momentarily while it cranks and then starts up fine.

But it's clear I have a problem. Searching the forums hasn't turned up anything similar or any solutions.

I've tapped the solenoid lightly: No change
I've got iceshark grounds installed now: No change
All contacts to the starter have been sanded and greased with di-electric grease: No change

So long as starters die randomly on me, this car is crippled. Any help would be greatly appreciated.

PorscheDoc

Are you replacing with rebuilt starters or used starters?

ninefiveone

Rebuilts. The third replacement was from Jason at Paragon as was the fourth.

Peckster

Bad switch now?

ninefiveone

Ignition switch? So obviously the ignition switch is part of the circuit but I'm not sure where you're going. Bad ignition switch killing starters?

I'm all for hearing more.

dmsog

Remove the small wire from the solenoid and hook the positive end of a voltmeter to it. Connect the negative side of the voltmeter to a known good ground. Turn the switch to the crank position and observe the reading. If it's not system voltage, you more than likely have a switch problem.

Doug

ninefiveone

I will definitely test that out.

But I have a question. If it's a bad switch, wouldn't it always just not start? Why does it start a few times and then kill the starter? The solenoid wire is just a trigger, correct?

RSflared72e

Assuming the starters are actually bad each time (sounds like that's a maybe?) - the voltage may be running high and burning up the starters- will be interesting to see where the voltage is at...I would also be surprised to see the ignition switch be the cause. Maybe the voltage regulator...

IceShark

That is right Hugh. You are bench testing the failed starters, right? If they don't work when you directly send juice to them then it is not the ignition switch.

Could be the solenoid that keeps failing or something internal but you need to take your last failed starter apart and see what the problem is.

As far as high voltage burning them out, seems very unlikely. But just test the voltage at the battery and see what it is. I'm not sure your battery can hold a voltage high enough to burn out the starter, unless you went and got a 24 volt one. But then you would be losing light bulbs and all sorts of electrical components. I bet the DME would fry.

The alternator and voltage regulator will have nothing to do with too high a voltage at startup when the starter is used. Our alternators can't even make much over 14.4v at a 40 amp draw and I can guarantee you that starter is pulling way more than 40 amps. We are talking hundreds of amps.

iloveporsches

Make sure you aren't tightening down the nuts that hold the wires to the solenoid too tight. I did that and it screwed up the post and I had to replace the solenoid. The other solenoid was off a rebuilt starter with maybe 30 starts on it.

ninefiveone

I've bench tested one of the dead starters and plan to bench test the latest. The one I bench tested worked fine on the bench.

iloveporsches

Might be a bad ignition switch then.

IceShark

OHHHH, that changes the story. Then you are either not getting good voltage through the main starter cable or something is wrong somewhere in the solenoid trigger/ignition switch.

The more I think about it this happened after your clutch job. I bet you fractured the solenoid trigger wire that runs down to, obviously, the solenoid. That would be easy to pinch in a clutch job.

dmsog

The starter is not necessarily being 'killed'. If the contacts in the ignition switch are bad and you're not getting full voltage to the solenoid (in the crank position) you will have this problem. This can be intermittent. Do my voltage test as stated above to determine if this is the problem.

Also, a bench test of a starter is relatively worthless. If the armature is shorting to ground, it will free run, but not even a click will be heard when you try to use it under load.

The fact that you have tried several different starters leads me to believe the problem is elsewhere, possibly the switch or the wiring between the switch and the starter.

28 years in the starter-alternator rebuilding business (so far) doing the talking here.

Doug

adrial

There's a white connector that connects the solenoid to the ignition switch; its located towards the rear, driver side of the engine compartment. It's near the brake booster IIRC.

Unplug that and run power direct from the battery to the thicker wire that runs back towards the starter...if it starts then you can be pretty sure its your ignition switch.

I've had to do this many times to my car, ignition switch works 95% of the time so I haven't bothered to replace it yet.

Let me know if you need more clarification...