last ditched atempt!!!!!!!!!!!!!!!
 

this is it. '68 911 with '75 2.7s and 915 box
the car will start when cold but as the engine gets hotter the starter gets lazier. i posted this prob about a week ago and got a great response but its still doing it and i don't know what else to do!! ive replaced the battery, and the armature and the solenoid replaced in the starter and had the alternator checked and new brushes installed. the alternator was putting out 12-13.5 volts. ive cleaned up the earths and put two new ones on, one from the neg battery to the body and one from the body to the engine. someone told me about a bosch relay kit that can help with warm start problems but i can't find anyone in the uk who knows what the f--k im going on about!

P.L.E.A.S.E H.E.L.P!!!!!!

Andy Domakin

try this:

Take it to a garage with a good reputation and ask them what the problem is and how much to fix.....but don't agree to the price. Instead, bring it back home and do the work yourself.

Have you checked the positive terminal on your battery. It could be that it is corroded internally. My neighbor had a similar problem. His truck would start cold but when hot the selenoid would not engage. He bought a new selenoid but it did not solve the problem.

I talked to him about it and when I checked his positive terminal, it was corroded all the way throuh from the battery post to the selenoid terminal - it was copper with a plastic cover over it.

Steve

Expanding on what Steve wrote, I had hot start problems as well. I looked at the small wires at the + terminal and they were pretty corroded. I cut a 1/2 inch off each of the smaller wires, cleaned them with a nail file and recrimped them and all was well thereafter.

Give it a try.

Pepsi or Coke!

Seriously, try pouring a little cola on the battery terminals next time it won't start, if it kicks over you have either a loose or corroded cable. Your alternator voltage sound a little low but not much, certainly not enough to cause this. Are you sure the starter was properly rebuilt? Generally hot start problems are caused by heat soaked old starters, it seems odd that a rebuilt starter would perform this way. Definately check the condition of your positive battery cable as stormcrow suggests, I to have seen these corrode from the inside out.

I agree with what was said before me, but if that isn't the answer, I humbly suggest the following: I don't know if you retrofitted the harness from the later engine to your earlier car, but if you did, take a look at the connector in the driver's side of the engine bay. Pull the 14pin (I think) connector off the aluminum housing and see if there is corrosion in there. I've also heard that concentrated lemon juice will do the trick if you let corroded wires sit in it overnight. When the problem is manifesting itself, you could also try a jumper wire from the pos. cable from the batt to the starter itself, right? At least this way you can eliminate the solenoid as a consideration and determine if the problem is upstream or downstream, so to speak. NOTE: Make sure the car is in neutral and/or the rear wheels are jacked up while you're under there.

Good luck,

David

thanks everyone. im off to have another fiddle.

If the starter drags and has less power, then the list of things it would NOT be includes the solenoid, ignition switch and wiring harness. In that case, either the starter MOTOR is not healthy, or it is not getting enough current. I strongly suggest the big, fat positiuve cable be examined and cleaned. Clean the terminals until they are shiny and beautiful. Same with the negative cable. Same with the ground strap between the tranny and the chassis.

I also disagree that 12.5 volts or less is enough. Even under load, your alternator should be making more than 13 volts. With no load, it should be making more than 13.5 volts. If your alternator is only making 12.5 volts, I'm not surprized you're having starting problems. Less than that and I'd be surprized if it started at all. Electricity moves more easily in cold temperatures. Weaknesses show up when things are warm. Hope this helps.

thanks s-man