lazy starter when hot, but its reconditioned

[adomakin]

can anyone give me some help with my starter on my 69 911. its got a 75 2.7s engine and 915 box fitted. when its cold the starter spins great, but when warm it spins slow and when hot it hardly spins. ive had the alternator looked at and its putting out between 12 and 13 volts, ive fitted a new battery (fully charged) and ive just had a new armature and solenoid fitted in the starter but its exactly the same as before any of the bits were replaced!

can anyone help??

Andy Domakin

[Sunroof]

Hey Andy
Same thing happened to me recently and I put out an SOS on this board. I had my alternator checked because the starter would just "click" after a run and then shut down. It turned out the battery had to be replaced. Okay.........I replaced the battery head down the road on a 300 mile road trip, stop to re-fuel and, the big "click" again. Nothing. Its always embarassing to ask for a push to get started!!!! I was not very happy and to remedy the situation I bought a spare battery kept it in the trunk and JUMPED myself until I got home.....................

I got under the car when I got home, cleaned all my fittings onthe battery and starter and replaced that old ground strap. Well that was my problem. The ground strap was beat, dirty and worn.

I also as another precaution purchased a "hot start" kit that is popular with the 914's. Its a little fused relay that attaches close to the starter, concentrates the battery power and provided an extra boost to the starter. Your starter/solenois wires attach tot he relay. They are cheap, made by Bosch and installs easily.

Try the cleaning first, replace the ground strap and see where that goes......

Regards
Bob
73.5T

[cab83_750]

Andy,

Consider yourself lucky. Mine used to crank super when cold, but once warm, I would not even click.

Try the recommendation above, that normally is the main problem. When I had this problem, it cost me lots of hours: I cleaned the ground, nothing. I replaced the ground strap, nothing. I installed the 'ignition relay', nothing. I replaced the starter with a high-torque, nothing.

Ultimately, it turned out that the new starter was also bad.

Search the archives. There's a lot of discussion on this! Good luck.

[Superman]

Your alternator should be making more than 13 volts. Look carefully at the connections and cabling. Measure voltages at the starter and report back. Measure them when the engine is hot, if possible.

[jluetjen]

Here's a possible solution as told to me by my car's PO (who happened to be an electronics engineer). He described that as originally wired, the voltage to the car's starter was being pulled down by the draw to the ignition system. I believe that he said that he fixed the problem by isolated the starter from the rest of the ignition system which solved the problem. Looking at the wiring diagram in the shop manual, I see that the starter is wired on the same circuit as the ignition system. There is a large black wire that runs from the battary to the starter, and then a red wire from that post which continues to the ignition system as well as the rear junction block (located in the left rear fender - you know the exposed post which has a live unswitched 12 volts going to it ). Anyhow, I do know that my '69E (with 9.9:1 CR) has never had a problem cranking, hot or cold.

Could someone with a stronger electronics background then I comment on this?

[adomakin]

thanks very much everyone, ill let you know how i get on!

Andy

[Early_S_Man]

Andy,

Indeed, your alternator should put out between 13.4 Volts and 14.6 Volts above 2000 rpm, per the factory service manual. Output at idle is another issue!

Calibration issues with your meter aside, your system Voltage should be a nominal 14 Volts when operating the engine at normal rpms.

Clean your battery terminals, connectors, ground cable connections at the batteries, and transaxle-to-body ground strap. Remove and clean ALL of the connections at the starter solenoid.

If you are still having hot-start problems after all of the above, remove starter, disassemble and clean and lubricate solenoid plunger and linkage, and the bendix mechanism with a premium-quality moly grease rated for high-temperature use (NLGI #2) ... such as Valvoline #986 SynPower Synthetic Grease with moly.

A starter cleaned and lubricated every two years will not give you any problems for many years! Good luck!

[adomakin]

cheers s man, ill give it a go