82' 911 sc starting problems!!!

Fher · 03-15-2008, 06:38 PM

Hi all,
I'm having issues when trying to start my car. Sometimes all I hear is a "humming" noise coming from the fuel pump and from the engine itself. The car will not start unless you push it (just a little bit) while pressing the clutch and car being in a gear and then releasing the clutch while trying to start the car using the car key. I have replaced the "Starter" & the car alarm. 1st I was told it was the starter, then that it was the car alarm (kill switch) that is why I replaced both but the problem still remains. Now I'm being told that it could be another "kill switch" one that came with the car from the factory. Can anyone give me a hand with this problem? I'm not sure what else to do? Thanks in advance for your assistance and GOD bless you!

Jesset100 · Jesset100's Garage

Fher, Welcome to the board! You might want to mention where you are located. Maybe a Pelican can come over and help you out.
I'm sorry I can't offer any suggestions but theirs a whole lot of smart people on this board that can.

jcunning · 03-15-2008, 07:25 PM

I think the first step should be to determine if your starter is getting 12 volts on the trigger wire (the smaller one) when trying to start the car.
Also make sure you are getting at least 12.8 volts on the big terminal.

If you are getting a solid 12+ volts, then you don't have any problem with kill switches or the ignition switch.

Then you can press (or have someone else press) the clutch pedal and see if the 12 volts comes and goes depending on how it is pressed.

If you are getting a solid 12 volts all of the time then you could have a bad starter solenoid, a bad tranny ground, or a weak battery.

boyt911sc · boyt911sc's Garage

Quote:

Originally Posted by jcunning

............
Then you can press (or have someone else press) the clutch pedal and see if the 12 volts comes and goes depending on how it is pressed.

JC,

Why would clutch pedal actuation cause any voltage change? Thanks.

Tony

jcunning · 03-16-2008, 04:10 AM

Just taking a guess by his description of the problem. By his description he needs to raise the clutch slightly before the car will start.

Maybe someone hooked up a clutch switch so you can't start the car without the clutch pressed in and now that switch is out of alignment or something.

psalt · 03-16-2008, 06:46 AM

Fher,

The first thing to suspect is the battery, then the battery wiring. Many 911 starter problems are really battery problems. If you don't know the condition of the battery under load, try a known good battery. Put the battery on a charger for a few minutes before trying to start, if the problem goes away, your battery is too weak to engage the starter under load. Be careful holding the key in the start position when the starter does not run. The cold start injector will be spraying fuel into the engine causing a flooding problem.

911quest · 07:10 AM

Sounds like you need to check your ring gear (striped teeth) basically what you doing is with the car in gear your making the motor turn just enough to get to some good teeth for the starter to mesh with..... the huming your hearing is probably the starter turning but not engaging with the ring gear.

Fher · 08:05 AM

Done, Location is now updated!!
Thanks for the advice!

tcar · 03-16-2008, 07:59 AM

I'm thinking ring gear also, typical if you have to move the car & 'pop' the clutch.

The 'humming' (buzzing?) noise from the engine is the frequency valve. Normal.

Fher · 03-16-2008, 08:01 AM

Could it be the battery even if when I turn the key to the ON position all the lights in the panel, stereo, power windows & head lights work fine? (please note that this problem in intermitent it happens very often but it is not concistent. I have not been able to find a pattern. Every time I take the car to the mechanic it works fine. Very weird and frustarting)
I will be checking the battery anyways just to make sure that is not the problem.
Thank you for the advice!

Fher · 03-16-2008, 08:03 AM

Whe you guys refer to the ring gear are you guys refering to the flywheel or is that something else? thanks!

911quest · 03-16-2008, 08:13 AM

It is a seperate part but you should plan on doing a clutch while your in there if that in fact is the problem....If you remove the starter and get some one else to rotate the engine slowly by hand while you look at the teeth on the ring gear....

#5

Fher · 03-16-2008, 08:20 AM

I will definetly check on that. If required...
How difficult is to replace the ring gear?

Thanks in advance!

psalt · 03-16-2008, 12:55 PM

Could it be the battery even if when I turn the key to the ON position all the lights in the panel, stereo, power windows & head lights work fine? (please note that this problem in intermitent it happens very often but it is not concistent.

Fher,

Yes, the starter, especially a 911 starter at the end of a long cable, takes many times the current of all other accessories. Try putting the battery on a charger for a few minutes before starting and see if the problem disappears. Even a "new" rebuilt Bosch starter can have this symptom because of the ground design, which is not touched during a rebuild.