Starting issues

[Tim Berardelli]

Neil,

Those cut-off switches are known to develop internal resistance that will preclude the battery from receiving a full charge. They are, as the late H. Pellow might say, NWS!

[David Jones]

Neil, check the charging voltage. Should be around 7.3 at 2000 rpm. As long as it is above about 6.6 volts you should be OK. With no battery maintainer a good lead acid or better still your optima should be good for months.

[Neil Bardsley]

Neil, check the charging voltage. Should be around 7.3 at 2000 rpm. As long as it is above about 6.6 volts you should be OK. With no battery maintainer a good lead acid or better still your optima should be good for months.

Thank you David. Today I checked, with a somewhat willing 12 year old assistant. I had 6.4v at the battery at idle when the car was above 2k it flicker to 6.46. Then I checked at the dyno and I had 7.6v max and about 7.3 at 2k (as you suggested). This is where my electronics knowledge is a bit thin. I have an amp meter on my dash which sound when I'm get a positive charge but how do I know how many volts are making it to the battery? Or is it really about the amp to show there is a flow in the right direction?

[David Jones]

Neil, the battery voltage will tell you if it is charging and an ammeter will tell you how much. The water analogy is the best way to describe it and you can google it and find many descriptions. A fully charged battery will put up resistance to current flow so an ammeter will only register a small current but the voltage should always be around 7.3 above 1100 rpm. If it is not then the voltage regulator will need adjusting. There are two circuits remember, one regulates voltage and the other current. Read the attached link which will be more than you need to know about generators and regulators. It sounds as though you have a wiring issue somewhere because if you have 7.3 at the genny then you ought to get 7.3 at the battery. Check voltage at the Batt post on the regulator then check it at the connection on the starter solenoid and lastly at the battery. You should see the same 7.3 volts everywhere.
http://www.venselenterprises.com/techti ... rators.pdf

[Neil Bardsley]

I seem to be losing about .3v from the dyno to after the regulator but then nothing over 6.5v leaves the starter to the battery. Strange as I thought the b terminal of the regulator was direct to the starter? I will check it tomorrow in the light of day

[C J Murray]

Get a correct battery ground cable without the multiple pieces and make sure the body is very clean where it bolts. Get rid of the disconnect terminal since as Tim said they are trouble. Get the correct Porsche positive terminal and make sure that the wire on the positive cable to the starter is super clean. Make sure the smaller cable is super clean also and that all the connections at the battery are superb, not good, superb.

Check and clean the large and small cables at the starter, superb connections not just good.

Look at your fuse box and think about soldering at the rivets and cleaning the fuse contact points.

Check the ignition switch for resistance and think about having it rebuilt.

Check your bullet connectors for corrosion.

You only have 6 volts to start with so the system has to be in good fettle to work.

[John Hearn]

Cliff
Great description on all the things to check on a electrical system.
Ten out of ten.
Your next problems is..........
How to stop Alfa's rusting......only kidding!
Maybe!
Happy Thanksgiving to all.
KTF
John

[David Green]

So here's another cause of hard starting I just solved with the help of a good friend:
First clue - while occupied on my '53 project I neglected to drive my 1959 A coupe, 912 engine, for maybe 6 months other than an occasional start and warm up in the garage.
Second clue - with the '53 done I went to get the '59 back on the road to use regularly and it had the dreaded starter "groan" 9 out of 10 start attempts. But on the 1, the starter would spin properly and start.
Third clue - thinking my 5 year-old trickle maintained Optima 6V was shot, I tried jumping it with a fresh 6V without improvement.
Not letting these register, I began the task of troubleshooting the electrical system, grounds, ignition switch/remote relay and starter and first checked the battery voltage drop with the starter turning. I didn't want the engine to start (1:10 chance) while checking the voltage so I pulled the coil wire and lo and behold the starter spun perfectly, just like it is supposed to. The battery voltage dropped from the fully charged 6.4v down to low 5s while cranking and then back to 6 when stopped.
I reconnected the coil wire and again got the dreaded "groan" when my good friend happen by and casually commented "check you ignition advance". He was spot on!
It now appears that while the car sat unused one of the distributor advance flyweights got gummed up on its pivot and would stick somewhere in the advance curve, not all the time (9:10), so the engine was trying to start with much too much spark advance and thus the starter "groan". If it happened to return to the static 5 degrees then the engine would start normally, I'd warm it up, rev it up, and the weight would stick so when turned off it stayed advanced and then next time "groan".
An easy cleaning and lubricating of the advance mechanism solved the problem (photo).
First mistake - I didn't drive the car!
David